2013 CLS250 fob reset

[MBCLS100]

2013 CLS 250. Sat for 14m. Both batteries dead and have been replaced also new fob battery.
had to use mechanical key to open the car but nothing happens when I put the fob in the ignition. Is there a reset protocol t

 

[DSM10000]

Keep you question too one part of the Forum or it can lead to answers being posted in different sections which can be confusing for all