How to remove flood tool selection?

[queen]

Hello, in ps I just click delete or backspace and it removes the selection (background) but on here it removes the whole layer and I can not figure out how to do it.

[GarryP]

Welcome to the forums @queen

If your layer is an Image Layer, and not a Pixel Layer, then pressing DELETE will delete the layer because you cannot make a pixel selection on an Image Layer; you are saying delete the selected layer rather than delete what is inside the selection.
If you want to make a pixel selection then you need to Rasterise the Image Layer to convert it to a Pixel Layer.
See attached image where the layer is an Image Layer – it has “(Image)” after its name. Right-click the layer in the Layers Panel and choose Rasterise from the menu as shown.

[queen]

Thank you @GarryP it worked but wish I didn't have to do this extra step. 

[GarryP]

You're welcome.

It might be nice not to have to do the extra step but the software needs to know which pixels you want to be selected.
Because the pixels in Image Layers might not be ‘aligned’ with the pixels in the document, the software is forcing you to make the rasterisation as you want it – rather than it doing its own thing and possibly getting it wrong.
It’s one extra step but it means that you are not bound to what the software thinks it should do with your work.