Inclusion Criteria:

1. Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the ICF. Participant has provided written informed consent and signed privacy/data protection documentation;
2. Male or female ≥18 to 80 years of age at the time of signing the informed consent;
3. Diagnosis of either EM or CM, per ICHD-3 criteria, for at least 12 months prior to the screening visit;
4. Diagnosis of migraine at ≤50 years of age;
5. Participants in the EM group: History of EM diagnosis and headache frequency (i.e. migraine and non-migraine headache): ≤14 headache days in the 4 weeks prior to randomisation on study Day 1 based on information recorded in the eDiary; migraine frequency: ≥6 migraine days in the 4 weeks prior to randomisation on study Day 1 based on information recorded in the eDiary;
6. Participants in the CM group: History of CM diagnosis and headache frequency (i.e. migraine and non-migraine headache): ≥15 headache days in the 4 weeks prior to randomisation on study Day 1 based on information recorded in the eDiary; migraine frequency: ≥8 migraine days in the 4 weeks prior to randomisation on study Day 1 based on information recorded in the eDiary;
7. Participant with a history of use of at least one preventive treatment for migraine.

Exclusion Criteria:

1. History or current diagnosis of migraine with brainstem aura, retinal migraine, complications of migraine, tension-type headache, trigeminal autonomic cephalalgias, hypnic headache, hemicrania continua or new daily persistent headache;

2. Headache attributed to another disorder (e.g. secondary headaches), except medication overuse headache (MOH);

3. Current uncontrolled psychiatric or psychological condition, or one that could confound assessment of headaches/migraines or interfere with study participation;

4. Risk of self-harm or harm to others as evidenced by past suicidal behaviour or endorsing items 3, 4, or 5 on the C-SSRS at screening or Day 1.

5. Participants presenting with a swallowing disorder of any origin which might be exacerbated by botulinum toxin treatment, such as:

   - Grade 3 or 4 on the Dysphagia Severity Scale (severe dysphagia) with swallowing difficulties and requiring a change in diet.

6. Clinically relevant skin condition or infection that could interfere with injection of study intervention;

7. Participant has any medical condition or situation that would make them unsuitable for participation in the study;

8. Participant receiving more than one allowable concomitant migraine preventive treatment;

9. Known history of an inadequate response to >4 medications prescribed for the prevention of migraine (2 of which have different mechanisms of action to botulinum toxin);

10. Use of any of the following medications in the specified timeframe prior to the screening visit:

    • Botulinum toxin for migraine within 24 weeks (or for any other medical/aesthetic reason within 16 weeks);
    • Prior use of mAbs blocking CGRP pathway within 12 weeks for preventative treatment of migraine
    • Prior use of oral CGRP receptor antagonist (gepants) for preventative treatment of migraine within 2 weeks;
    • Anaesthetic or steroid injection in any region targeted for treatment with study medication within 4 weeks;
    • Use of cannabidiol or other types of cannabinoids within 30 days;
    • Use of medical device to treat migraine within 4 weeks (e.g. non-invasive neuromodulation therapies such as nerve stimulation (gammaCore), transcranial magnetic stimulation (cephaly), external trigeminal nerve stimulation, transcutaneous electrical nerve stimulation and peripheral neuroelectrical stimulation);
    • Use of other intervention to treat migraine that is assessed to interfere with study evaluations within 4 weeks (e.g. acupuncture in the head and neck region, cranial traction, nociceptive trigeminal inhibition, occipital nerve block treatments and dental splints for headache);
    • Use of opioids or barbiturates for more than 2 days/month within the last 4 weeks.

11. Concurrent participation in another interventional clinical study (or within specified timeframe according to national or local legislation or requirements);

12. Diagnosis of other significant pain disorders that could confound the assessment of headaches/migraines or interfere with study participation, including but not limited to chronic pain disorders such as fibromyalgia, chronic low back pain and complex regional pain syndrome;

13. Pregnant women, nursing women, premenopausal women, or WOCBP (i.e. not surgically sterile or 1 year postmenopausal) not willing to practice an acceptable contraceptive method, at the beginning of the study and for a minimum of 12 weeks following the administration of study treatment;

14. Male subjects who are not vasectomised and who have female partners of childbearing potential and are not willing to use condoms with spermicide for a minimum of 12 weeks following the initial double-blind administration of the treatment;

15. History of alcohol or drug abuse within 5 years of the screening visit (excluding medication overuse for headache);

16. Body mass index (BMI) ≥35 kg/m² at the screening visit;

17. Known clinically significant hypersensitivity to any of the study drugs, excipients or materials used to administer the study drug;

18. Patients who, in the clinician's judgment, are actively suicidal, and therefore, deemed to be at significant risk for suicide.

19. A diagnosis of a neuromuscular disorder or respiratory disorder, such as myasthenia gravis, Lambert-Eaton syndrome or amyotrophic lateral sclerosis that in the opinion of the investigator would compromise the safety of the study participant.