How to connect and control a servo with APM 2.6 FC?

Hello. Please help me figure it out. Quadrocopter Ardupilot apm 2.6. During automatic transmission, the servo does not work on the do set servo command. The servo is connected to the 8 channel output. I will be grateful for your help.

Test the servo with a servo tester first.

After that update to a newer supported flight controller hardware and install ArduCopter 4.3.4-rc1 or newer.

Then you can follow the excellent instructions on the ArduCopter wiki on how to connect and control a servo.

The servo itself is working. How to make it work on apm2.6 by the do set servo command

The firmware version you are using is from the year 2014.
All developers (without exception) are using one of the over 90 supported newer hardware boards.
Almost all users have have migrated as well.

Search this forum, it is you only option.

Here is the archived page for the APM flight controller. Perhaps it will help. But I would suggest replacing it with a supported board.
APM Archived