What are fee_method and fee_level in Electrum's getfeerate RPC call? I couldn't find any documentation on this.
I found that the options for fee_method are eta, static and mempool by reading the source code. But it's still not clear to me how fee_level relates to the fee_method, does it have something to do with configuration? If that's the case, the configuration isn't documented either. What is to be set? How does it work?
There are 3 options(fee estimation methods) available for fee_method: static, eta and mempool
static - static fees
eta - based on confirmation within N blocks
mempool - based on mempool depth

fee_level for ETA can be one of these values in Electrum GUI: 25,10,5,2
FEE_ETA_TARGETS = [25, 10, 5, 2]
https://github.com/spesmilo/electrum/blob/ea22d0073ea5f61d53449a7afd072c3fd78003e8/electrum/simple_config.py#L23

fee_level for Mempool can have one of the value mentioned below in Electrum GUI:
FEE_DEPTH_TARGETS = [10000000, 5000000, 2000000, 1000000, 500000, 200000, 100000]
https://github.com/spesmilo/electrum/blob/ea22d0073ea5f61d53449a7afd072c3fd78003e8/electrum/simple_config.py#L24