How to validate the attached file is jpg on ui builder experience and show pop up if it is not jpg

[sony8]

Hi ,

I have below requirement,

I created a variable of type attachment, and variable attributes I have added add extension =jpg.

when I am attaching the file other jpg it was not attaching, if it is jpg it is allowing to attach.

I want an error message when a user attach other than jpg.

how to validate this on ui builder experience?

[sony8]

@Samaksh Wani I have tried both .

variable attribute added in the variable. It was not allowing other than JPG , field message is not coming when i attach other than JPG. 

I want field error message to be appear on the variable when i attach other than JPG.

Problem i am facing: working fine on portal if i add variable attribute but not working on UI builder form.

[Dibyaratnam]

How are you adding that attachment on workspace, can you give some more details with screenshot.