Hello @Anonymous ,
Yes, it's possible to edit a SharePoint list from a canvas app. For that, you can use the "Form" control.
Forms are the simplest way to view/edit records, but also the most rigid. Basically, you use your form in "Edit" mode to update a record, then click on a button with "SubmitForm()" to update the datasource.
However, it is also absolutely possible to build your own form for this purpose with "Patch()". Just keep in mind that "Patch()" is a bit tricky to use:
Patch(datasource, Defaults(datasource), {...}) //Creates new record
Patch(datasource, ThisItem, {...}) //Edit existing record
If you're still new to this, I suggest looking at the app samples provided by Power Apps. They give a few insights on how this whole operates and can be quite helpful for the first steps.
