How to create a custom bridge between two EVM-based blockcahin?

I have two private testnets running on a network - one is Ethereum using PoW consensus and the other is running Ethereum with PoS consensus

i want to create a bridge between them - say i want to move ether, from the chain running PoW to the chain running PoS.

how can i achieve this? do i have to learn to write a bridge - that will allow interoperability between these two chains ? If so, how can i learn to write a bridge between these two blockchains ?

if there is a more suitable alternative solution to this, please let me know!