Getting paid on time is one of the quieter admin problems in a hypnotherapy practice. Cash and bank transfer work, but they put the burden of chasing payment on you and leave no automatic record tied to the session it was for.
Bank transfer with manual reminders has no fees but every step is manual. A generic payment link tool is faster but has no idea who the client is in your practice. Payments built into your practice-management system are generated from the client's record and the specific appointment, so there is nothing to reconcile by hand.
Stripe is PCI-DSS compliant, so you never handle or store a client's card details directly. What is left is how you handle the client's personal and clinical data connected to that payment, which is a GDPR question, not a Stripe question.
Trance OS connects to your own Stripe account and lets you send an invoice or payment link directly from a client's record, on the Basic and Professional plans. See pricing.