It appears your mixer is the wrong type for your requirements. Your line mixer is designed to work with line level devices which is different from microphone levels.

You need a mixer like this one.

https://www.amazon.com/Professional-ALPOWL-Interface-Bluetooth-Streaming/dp/B08F9X3LZ6

I don't have experience with the mixer but I've used the speaker and it works well

https://www.amazon.com/Professional-ALPOWL-Interface-Bluetooth-Streaming/dp/B08F9X3LZ6?th=1

https://www.amazon.com/Rockville-RPG10BT-V2-Bluetooth-Wireless/dp/B088ZH5CGH