Chosen Solution
My MacBook Pro’s headphones jack is not working properly. Any headphones or speakers connected to the laptop using that jack makes no sound. However, it is able to detect the headphones when inserted (when I check System Preferences > Sounds and Audio MIDI Setup, it’s there). The mic also functions properly, e.g. the mic on the EarPods works well. Any chance this can still be worked on without handing it in for repair at the Apple Store?
A workaround would be to use a USB audio adapter (dongle). USB audio is separate from analogue and the dongle would have a headphone jack (line in/out - some even have a built-in mic). If this answer is acceptable please remember to return and mark it.