Can I claim overtime if I’m on call during a business trip?

[Z] was hired as an export sales assistant by Calibracier (the company) with effect from September 6, 2004.
On January 1, 2014, he was promoted to Deputy General Manager.

On December 6, 2018, the employee brought a claim before the labour court relating to the performance and termination of his employment contract.

He was dismissed on January 21, 2019.