Online Program anyone can access on Multiple devices using same ID and password. there is any option to restrict this unwanted course access from some fraud user

i create website for 1 of my client, he told me my many student share own id and password with there friends and family Members . in this case my client get huge loss.
i think we need to restrict this. if 1 Members access this program on 1 device in that same time nobody access this same program on another devices.
Plz help me my many customer start to left wix platform because of this 1 problem.

In this case, you will have to maintain a database that will save a value (probably the details of the device the user is currently on) when the user has logged in and then erase the value when the user has logged out. This can be done using custom code with Wix Velo.

Thank you so much definitely i will try to solve this.