How to implement A/B testing for a front end/ backend application

This is more of a general question for a project I am currently working on.

I basically have a Spring Boot Rest API with a Front end and I want to carry out A/B testing on a particular "view Item" page on my front end.

However I am not sure where I would begin or how I would carry this out.

Do I require a login page on my front end to log different users and their interaction from the backend? I am basically want to determine the users' flow through the web browser and which page is more popular with users.

What sort of technologies would be able to incorporate this?

Ideally I want to program this functionality myself but I don't have a great deal of experience in this area.

All help would be greatly appreciated!