Epoxy
Looking at the close up, I believe the two pop rivets are the truly structural strength in the joint.
If I was going to get into this, I’d be looking to replace those rivets.
Getting the pop rivet gun in there might be tough. But a small length of metal tube could be used to extend the gun (if it’s still able to grab the rivet).
But if you’re really going to use epoxy for a highly stressed location…….
When mixing epoxy, don't mix the amount you need…. Mix more.
Mix well, folding from edges to middle.
scoop from middle of very well mixed pile, and mix the scooped amount again.
Then take from middle of that double mixed pile for the repair/project.
For such a small repair, you will throw away more than you use.
Select a slow setting epoxy (45+min if you can find it)
Keep the part within the epoxy temp range for the recommended full setting time.
Don’t keep it warm for 45mins then move it to a cold garage (don’t ask).
Barry