The smokes are 2Gig SMK T3-345
First, what is the printed date code on this unit? If it is expired, it will need to be replaced.
Steps to learn a SMKT3-345 would be as follows:
At the panel navigate to Settings > Installer Code > Installer Toolbox > Panel Programming Wireless Zones > Select the first unused zone.
Programming choices can be found below, the video is for the GC3 but programming choices are identical:
After pressing the learn button for the TXID section, make sure you are tampering the SMKT3 by removing the sensor from its backplate to get it to communicate with the panel.