Hi there.
Thanks for the clear pic.
Don't worry it appears easily resolved.
Appears to be what we label Intertrigo.
Could be bacterial of fungal or a combination thereof.
More details on history will be required.
Next Steps
an INSTANT ONLINE Consultation is best for a speedy resolution
Health Tips
Avoid OTC products and home remedies
Antihistamine like Fexofenadine 180 mg will help with the itching.
A cream like Eumosone-M may be helpful as an immediate intervention but do get a prescription and don't use past a point as suggested by a Qualified Dermatologist 🙏