Please launch your browser and enter http://covr.local./ into the address bar. Then login and follow the steps below:
Step 1: From the home page, click the Connected Clients icon:

Step 2: Click the Pencil Icon in the box of the client you want to change settings for:

Step 3: Click Reserve IP to enable IP reservation. Enter the reserved IP address, then click Save. By doing this, the DHCP server will reserve the IP address you entered for this client device.