How to stop iPhone screen from turning off?

so if you're trying to stop iphone screen from turning off you can go to settings and then display in brightness but here you have out to lock 30 seconds like why is that and you can't change that so auto lock 30 seconds means that your phone is in low power mode auto lock is restricted to 30 seconds so basically it means that your battery is low power mode so tap on battery disable low power mode and then yeah you can just go to display and brightness yes you can see my uh yeah my battery requires some service so then here you have auto lock you can change it like for something like that or you can just change it for never or yeah so there you have it hope this is helpful