Mining Software – What is the format of the Bitcoin block body?

From what I understand, miners solve the nonce to get a valid block header based on the difficulty goal. The header contains the Merkle root generated from the transactions included in the block. Based on the document, nodes verify the transaction. Does this mean miners don’t need to verify transactions in the mempool?

I’ve been searching for examples of what block submission looks like. I know that blocks can be submitted via RPC. But even if this isn’t practical, let’s say you’re building a miner. Does anyone know what format is used to submit blocks specifically? Are there any known real-world implementations that the puppets can understand? Looking for code etc.