Help with Lightroom Classic V. 13.5.1 eraser tool

I cannot seem to erase a simple black text (without a background) on many png files I downloaded from Kittl.  All I want to do is just erase the text on one image in the Develop module, and then use the "Sync" button with all of the images in the Filmstrip at the bottom of LR to replicate the same task. 

I've tried a few different approaches to do so without any success for something that should be easy.  Can anyone help me?  (I think Adobe added some features I haven't used before such as this, and now I'm lost.)

Thanks!