Video tutorial available on YouTube 👉 https://youtu.be/IHQS20kCVko
Method 1: Slider within the layer panel
Start by opening the layer panel by tapping on the two squares.
Tap on the small "N" on the right of the layer you want to adjust
Adjust the opacity slider!
Method 2: Opacity gesture
Start by opening the layer panel by tapping on the two squares. Then:
Using two fingers, tap on the layer you want to adjust
Slide one finger on the screen to change the opacity of your layer (left: decrease, right: increase)