How's the process if i want to have openwrt on a lot of routers
Each one is loaded and then configured individually. If you need a configuration that is different than OpenWrt's standard default, you can "bake in" those configuration details into your firmware image by building custom images. That said, all of them will come up with the same IP address, which means that they must either be further configured prior to connecting to the main network, or switched to use DHCP client for their IP address as part of your baked-in configuration.
You wouldn't normally deploy a whole bunch of routers all serving just a single site, unless the site is a massive campus on the order of 1000+ hosts. Do you mean deploy one or two routers each to many different offices? Or do you mean deploy many access points spread out across the office?
Depends on how different you want them to be.
Likely you need OpenWISP to manage them.
For more info, refer to the OpenWISP documentation.
thank you for all your kind responses, i want them to be in a lot of different routers across a building, should i do this process manually on every router ?
How many is a lot?
And do you want routers or wireless access points?
If you’re struggling with the difference and the design you likely need to engage a professional
If you do it manually, how will you maintain them up to date when critical security vulnerabilities are patched?
What if they ask you some configuration change?
How do you know if the routers are working fine or not?
If it's something amateurish you can definitely do it manually and then maintain it best effort, but if this is anything professional and you don't set up an efficient way to maintain the network you're headed for future troubles.
My 2cents.