I see a lot of videos and tutorials of people using the mask tool. In mine it just doesn't show any button for it. I'm sending a screenshot so you can see and help me... if possible.... thank you!
Lightroom has one kind of mask, Lightroom Classic has two, so it will help to be more specific:
If you’re asking about the Range Mask tool, I think only Lightroom Classic has that.
If you’re asking about the mask that you can edit with a brush, that is part of every local adjustment (Adjustment Brush, Radial, or Gradient mask), so in either Lightroom or Lightroom Classic, you can see and edit that mask only after you have added a local adjustment.
You are in the wrong forum. This is the forum for Lightroom Classic. I suggest you ask in the Lightroom forum. (Although I suspect Lightroom does not have a range mask)