Enable local admin account

You should be able to use GPO for this.
http://tompopov.blogspot.com/2011/03/enable-windows-7-administrator-account.html

Or you can try Local Administrator Password Solution (LAPS) by Microsoft:
https://www.microsoft.com/en-us/download/details.aspx?id=46899

Alternative 3rd party solution:
Netwrix Bulk Password Reset
https://www.netwrix.com/local_admin_bulk_password_reset_freeware.html

https://community.spiceworks.com/topic/530062-changing-the-local-admin-passwords-across-the-network

I like the last one. It seems to be really simple to use.

I just want to enable the local admin , I have a third party solution to reset the password, unfortunately it will not enable the disabled account.

Then use GPO for this.

If you prefer enable local admin account with a command line, there is an option:

net user administrator /active:yes

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what is the nature of the disabled account? why not create/add a new one and manage it.
https://www.experts-exchange.com/articles/31583/Active-Directory-Securely-Set-Local-Account-Passwords.html

Thank you all, my question is how to enable a local account using PS script for a few computers?
Something like
Get-ADComputer -Filter { (ObjectClass -eq "Computer")
then output the result in a txt file and enable the admin account one at a time.

See if the following helps, reads data from text file
https://gallery.technet.microsoft.com/scriptcenter/List-of-Users-from-Remote-66def6c2

GPO will do the job.

Create a new GPO and go to: Computer configuration -> Policies -> Windows Settings -> Security Settings -> Security Options. On Right Pane click on Accounts: Administrator account status and change the settings to Enabled. Apply the policy to all desired computers.

If you want a script, deploy the startup script with GPO that contains:

net user administrator /active:yes

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