How can I change the Start Up Login/Lockscreen Screen Picture?

As of right now, whenever I turn the computer on, the default initial login/lockscreen picture is some colorful picture from MacOS Monterey. That’s cool and all, but I want to change it to my own picture so that as soon as I turn it on, I see said picture https://vidmate.onl/ . So far, the login/lockscreen picture only changes to the one that I prefer after having logged in for the first time (after starting up the computer). https://mobdro.onl/

Is there some hack to change the start up login/lockscreen picture to my own preferred picture?