Alpha Lock can be accessed by on the layer thumbnail and selecting the option (or two finger swipe to the right if you want to get fancy). After this, the transparency is no longer visible. After that, press your layer again and pick the “Fill Layer” option. You may also use this tool to paint a rough grain onto a layer if you want to.
Is there a paint bucket tool in Procreate?
In Procreate, you may color-fill a form with a color of your choice by using the paint bucket tool. Do you remember the color picker tool in the upper-right corner? Tap and hold down on the circle using your Apple Pencil, a pen, or just your finger. Then, while holding down the mouse button, drag the color to the outline of the form you want to fill in.