Is it obligatory for us to make the call to prayer (adhan) for the Dhuhr and Asr prayers in the workplace prayer room?

The adhan (call to prayer) in mosques is a communal obligation (fard kifaya); everyone incurs sin if it is abandoned, and the sin is lifted if even one person performs it. As for prayer rooms (musallas), it is not obligatory, but rather permissible and recommended, due to the general saying of the Prophet, peace and blessings be upon him, to Malik bin Al-Huwayrith and his companions: "When the time for prayer comes, let one of you call the adhan for you, and let the eldest among you lead you in prayer." The adhan does not affect the validity of the prayer, whether it is obligatory or recommended.