Help to finish the integration on rest api

I need to help me finish the integration on rest api b24
I cant keep up with the deadline.

Knowledge of cms Prestashop is necessary.
All the basic functionality is made and works, you need to finish the connection of individual elements. I missed something and I cant figure out where to go next.

If you havent worked with Prestashop before, dont respond.

Ill write down what youre going to do.
Im evaluating the work in about a couple of hours.
It would be great if I even unshairted the screen with the code and you would tell me that it is wrong and what needs to be fixed.