Hi - I just tried it and I dont have any errors in my flow anymore. However, in the output email, it seems that the formatting didn't work. I really appreciate your help and I'm sorry if took too much of your time.
This is how it looked like in the email it sent out:

In my flow, here's what I did:

Was there something wrong with the expression?
formatDateTime(items('Apply_to_each_4')?['Date'],'MM-dd-yyyy')
I used 'Date' in the expression because I wanted to apply it in the dynamic content / column "Date"