connect a microphone to two bluetooth speakers (not at the same time)

I'm looking for help to connect a wireless microphone to two Bluetooth speakers. The speakers have Bluetooth capabilities, however, they won't be connected at the same time. Sometimes I want to connect the microphone to one, sometimes the other. Therefore, I need advice on how to connect a microphone to bluetooth speakers. I am asking this question because I tried with my Samsung phone and a microphone / megaphone smartphone app, and the ECHO-OH-OH IS BA-A-A-AD. The echo was bad with the smartphone both with bluetooth and wired through the 3.5mm jack. I think I might get better results with a better microphone, but most microphones come with a 6.5mm jack and my speakers are 3.5mm. I searched if I can connect a 6.5 - 3.5mm adapter but most sites said I need something different, such as a mixer, because the mic power is low and the speaker power is high, so it needs a converter to make the mic power up to the speaker power, not just a simple plug adapter. I don't know, so I have come to post this question as a project. I attach pics of the speaker systems I need to connect a microphone to, both have bluetooth and both have 3.5mm input sockets, so I could theoretically connect any mic wired or with bluetooth, although as I say I'm trying to avoid echo while finding the cheapest possible solution. I need someone who is experienced with wireless and wired audio technology and is confident that they can complete this project without any problems (the project is basically providing advice as to how to connect a mic to the speakers). The speakers are Majority Snowdon II Wireless Audio Soundbar, and Anker Soundcore. The Majority is powered at the wall, and the Soundcore is portable and charged with usb. I haven't got a mic yet, I'm asking you what you think I could connect to it as a smartphone causes terrible echo. All replies welcome, thanks