SharePoint SPFx need help creating proper permissions group for app

Question

I created a SharePoint SPFx react app. Long story short, the application has a complex form for the user to fill out.

Initially I had set all users as "visitors" because I do not want them to have any access to any SharePoint options or to even be able to view site contents and things of that nature.

However, when filling out the form and pressing submit I'm doing something like this in my code:

pnp.sp.web.lists.getByTitle("Contracts").items.add({
    //pushing items to a the contracts list
}));

Well, since this action needs write access, the user is unable to submit the form. I was thinking I can maybe create a new permissions group, but the edit permissions gives them too much access, what are my options in this case?

Answer 1

Create a custom permission level in SharePoint.

You can copy the existing contribute or edit permission level to create a new permission level and uncheck the unnecessary permissions from settings.

Follow below article for detailed steps: How to create a custom permission level in SharePoint

Answer 2

yeah, you should break inheritance on that list and give users update permissions on just that list.

the other alternative is to call an azure function to do the update.