How to make a functional login/register form

Hello all,

I am new around here. So glad to be part of this community.

I am a graphic designer with 5 years of professional experience and recently I decided to experiment with UI UX because I was always fascinated about what you can do in this field, and why not connect UX with my current work.

So after 2 specialisations at UX fundamentals I decided to design a cafeteria delivery app. I am doing so well so far but I have a huge issue (with a possibly very simple solution). I need to make a functional login/register page for the app. I have made the design but I don’t know how to make the forms functional. I just cannot figure out how to add my text to the forms when I am in the prototype option. I need to find out how in order to proceed to the next pages. This might not be possible until the app is launched, I have no idea.

I will really appreciate it if you guys find a solution for me. Should I just continue with the next pages and worry about this issue at the end of the project?

Also, I have another simple question. Since this app might be a real one in the future. How can I guarantee that the credentials of the people with an account in the app will be 100% safe?

I don’t know if these questions are my job to the project as a designer or the developers’ job.

Thank you so much in advance for your time, and once again really glad to be part of the community.

Best Harrys