Is there any way to have signature panel ( like Canvas) in SAIL form or portal F

Hi arkaprobham does it have to do anything with a digital signature?

Yes

AFAIK Nop!!!

There is no such component available now on SAIL. Instead, You can make it as a document and send it for digital signature.

If you meant to do this on mobile devices with Appian native apps, you can just use document attachment. On mobile app, user can choose to use finger- or stylus-drawn signature for document attachment.