@mercermike
Never tried to link multiple BT speakers myself, but here's a [https://myhomespeakers.com/connect-multiple-bluetooth-speakers-to-pc/|link] that may help, if you haven't tried this already.
Unfortunately when you get to the part about the BT speaker having an app to select the "multiple outlets' option, your particular model is not supported by the [https://play.google.com/store/apps/details?id=com.oceanwing.soundcore&hl=en_AU&gl=US|Android] or [https://apps.apple.com/us/app/soundcore/id1331876603|Apple] Anker Soundcore app.
The speaker is using BT Ver. 5.
Also there is no software support for the [https://www.anker.com/es/products/variant/soundcore-2-portable-bluetooth-speaker/A3105091|speaker] from the manufacturer, which may have helped to update it to work with the app.etc. You could always try contacting the developer shown in the apps linked above and ask if the app can be modified to work with your model. Worth asking anyway ;-)