This is your primary pool settings. For ckpool and Public-Pool, the stratum URL is automatically set for you via the dropdown menu.

This is your BTC address you want to associate with your solo mining efforts. This is the address the Block reward will be paid out to if your Bitaxe hits a Block

This is an optional field, usually left blank with most mining pools

This is the settings for the backup mining pool that the Bitaxe will connect to when the first pool can not be found. The setting areas are the same as the Stratum URL section

The device needs to be restarted in order for the new pool settings to take effect. This typically takes around 2 minutes.