using nirgendswo/valitron and not vlucas/valitron

Hello,
I have a big problem, I want to use the Utrust paiement plateform in my application. I use composer to install codeigniter.
My problem is that Utrust use nirgendswo/valitron wich is a fork of vlucas/valitron. The two librairy use the same name of class: Valitron.
Then I tried to modify composer setting to use nirgendswo/valitron wich instead of vlucas/valitron with no sucess.
Now I think my best chance of success is to install nirgendswo/valitron manualy and deactivated vlucas/valitron.
Or create alias for the second class like valitron2.
I have absolute no idea how to proceed, please help.
Thank you by advance.
Laurent.

Init class in your code as alias?
Example:

use Vlucas\Valitron as ValitronVlucas

Simple CI 4 project for beginners codeigniter-expenses ( topic )