Hearthstone Glowing Card Borders

Hello,

Im currently creating a 2D card game.

I would like to know how I can make a copy of the Hearthstone glowing card effects. I know these days there is 2D lightning which you can enhance with Bloom and post processing, the thing is that i'm working in a 2D environment with Unity UI instead of Sprite Renderers.

I have tried creating multiple outline shaders with the Shader graph, however the edges of the outline shader are cut off , so i cannot create a bigger outline than a few pixels ( both examples in images below). I need the outline around my Card Borders which are dynamic.

I need to create a effect where its very obvious for the player to choose a card.

Would really appreciate it if somebody can help!