@Fisnik Magashi Thank you for reaching out to us on Microsoft Q&A. We apologize for the delay in response.
I understand that you are trying to connect from P2S client to on-prem via S2S VPN. However, this requires the S2S VPN to be using BGP as given here in this document. At the moment there is no work around for this and therefore will not work without BGP.
I hope this answered your questions. Please let us know if you have any further questions and we will be glad to assist you further. Thank you!
Remember:
Please accept an answer if correct. Original posters help the community find answers faster by identifying the correct answer. Here is how.
Want a reminder to come back and check responses? Here is how to subscribe to a notification.