While installing, configure all the signatures which might be used. If required, these can be configured and changed later by navigating to the install app menu > settings page. Once installed, the signature management icon appears on the text editor when replying to a ticket. Click the app to view all the options of the signatures which were saved. Select the signature that you want to use and click Add Signature. Note that the signature appears at the current position of the cursor. So, place the cursor in the right position and then select the signature. Also, it does not replace any text, so delete the old signature and include the new one.