How do I collect email consent for my app?

Should I just write a note under the sign up form and then say they consented?

I like this idea because it lowers the number of steps the user needs to do.

I don't plan on making much noise, just probably a welcome email after an hour asking how things went, and then when features come out I think I could send updates to inform users.

What do you think? Any resources?

Btw It is ranking on producthunt! Got a lot of work to do!

https://www.producthunt.com/posts/forky

Thanks!