How to control movement of robot based on the distance of april tag

Hi everyone, as previous posted, i am working on a project which aims to achieve auto-homing of submersible. May i seek any advice on how can i configure the code where the movement of submersible is based on the distance/size of the april tag on the OpenMV IDE?

Please see the AprilTag examples. For board control, please see the board control examples. You need to be able to take the code form the examples and build what you want to do.