
I customized SharePoint form using Power Apps. However, if I hit the save button in the SharePoint N times while loading, it will end up submitting the data N times. I used Patch function in OnSave setting, what functions can I incorporate in save button to prevent duplicate entry?
You could try resetting the controls after the patch function.
Reset(Control1);
Reset(Control2)
Etc.
If you are using the form in PowerApps you can use : ResetForm(FormName)
You could also use data validation on the sharepoint list to prevent duplicate entries.