If you open the share sheet, there should be an Open in Apollo option in the same place as your share sheet Shortcuts and below most of the other app icons. You

If you open the share sheet, there should be an Open in Apollo option in the same place as your share sheet Shortcuts and below most of the other app icons. You have to make one more tap, but it's worth it to not have to deal with Reddit's official mobile website (or worse, the AMP version).