Assigned Static Ip for All Clients using Mikrotik routerboard

Hello,
I am new and i start wisp in my area somebody configure routerboard each and everything going fine but there is is a question i have asked about it from alot of people but did not get any unique answer

I have 3 4 clients those have medicine store and they installed camera’s now they required static ip so how can i give them static ip i have bought 8pool ip from my isp and one ip is using in routerboard but how can i give the static ip to my clients is there any device which i need to connect my mikrotik server or please guide me in simple words i will be thankfull to you.