Step 1: Login to your email account with roundcube interface.
Step 2: Click Settings option in the left panel.
Step 3: Select Identities, click the identifies name added in your webmail account.
Step 4: You will see the settings option.
Step 5: In the signature field, add the signature that you wish to add in webmail account.
Step 6: Finally click Save option.
Click here to view this article as Oryon knowledge base video tutorial playlist.