Is there a guide about how to use laser?

Yes, here is a step-by-step guide on how to set up and use the 5mW/Class 3B Laser with various mounts:

Initial Setup
Step 1: Unscrew the laser tube cap and remove the small round paper protector inside.

Step 2: Unscrew the laser head cap.

Connecting to Your Mount
Depending on your specific equipment, use the appropriate adapter:

NOMAD: Use the red laser adapter to screw the laser directly onto the NOMAD unit.

Skywatcher: Use the SW laser adapter to connect the laser to your Skywatcher mount.

iOptron SkyGuider Pro: Use the IO laser adapter to connect the laser (this applies to the version with the threaded part located inside).