Shoulkerturtle314
I had a similar issue (was asked to Install the Play app 4-5times)
It was related to the permissions, which default to not-allow Installation from the source you're attempting. If you look in the notification tray, you will see a message that prompts you to review/edit/change this permission with a toggle.
I know you probably resolved this months ago, but for others who run into this in the future (as I did), I thought I'd add a comment.