How do I make a feathered sprite mask

Alright, so I have a mask I want to use to create a certain effect in my game. The only issue is the semi-transparent pixels seem to be registering as fully solid in unity. (By which i mean, it shows up as if the semi-transparent white pixels were not transparent, being a fully solid circle.)
This is the image I’m trying to use for my mask:
7955545--1019222--upload_2022-3-10_17-20-30.png
I’d like for my mask to take the semi transparent pixels into account so the sprite behind looks like it fades out. Am I doing something wrong, or do I need to use something other than a normal sprite mask in order to get it working?

that feature is not available in unity

Sadly that is indeed not included in Unity :frowning:
There is one semi pricy asset out there: