Step 1: Upload the signature image to a publicly accessible location. Example : TinyPic, Dropbox, Google Drive etc.
Step 2: Navigate to Manage >> Categories, and click edit next to the category you're looking to add the signature image for.
Step 3: Under Signature, click the HTML source editor button.
Step 4: Add the signature link inside a <img src=""> tag as below:
Replace your-image-URL-source here with the direct link to your category signature image. With your image URL and the tag, it should look something like this:
Step 5: Click Update and the signature will then appear, which you can then resize by dragging the corners.
Once you’ve done all the editing in the Signature field, scroll down to the bottom of the page and click Save Settings.