i tried the firmware password on my iMac computer but didnt work

Rykad2023 wrote:

Is there a way to deactivate the firmware password from my iMac computer?

for FileVault—You have to let it complete the encryption before you can disable it, after you have turned it on...

For your Firmware is different/different password

set firmware psswd /turnoff firmware psswd

see—"How to turn off a firmware password"

Set a firmware password on your Mac - Apple Support

If you can't remember your firmware password, schedule an in-person service appointment with an Apple Store or Apple Authorized Service Provider ( https://locate.apple.com/?apt_Flag=true )

Bring your Mac to the appointment, and bring your original receipt or invoice as proof of purchase.

How to turn off a firmware password

1. Start up from macOS Recovery. During startup, you will be prompted to enter the firmware password.
2. When the utilities window appears, click Utilities in the menu bar, then choose Startup Security Utility or Firmware Password Utility.
3. Click Turn Off Firmware Password.
4. Enter the firmware password again when prompted.
5. Quit the utility, then choose Apple menu  > Restart.

If you forgot your firmware password

If you can't remember your firmware password, schedule an in-person service appointment with an Apple Store or Apple Authorized Service Provider. Bring your Mac to the appointment, and bring your original receipt or invoice as proof of purchase.

What password? leroydougle already provided instructions if you forgot firmware password.

For forgotten login password:

If you forgot your Mac login password - Apple Support