How to add barrel adjuster to 11-speed Deore with drop bars?

Hey everyone,

I bought an old MTB last year and converted it to drop bars with an 11-speed Deore derailleur (RD-M5120).

After setting everything up, I realized there’s no way to fine-tune the indexing since there’s no barrel adjuster on the derailleur or shifters. It seems like the system expects the adjuster to be on the handlebars.

Does anyone know of a workaround? I tried adding an inline barrel adjuster at the derailleur, but it didn’t fit properly, and turning it had no effect.

I understand I can adjust the limit screws and the initial cable tension, but despite my best efforts, the shifting still isn’t dialed in. Any advice?

I would love to keep my shifters, and not resort to friction shifters.