The CD that came with the device listed RTL8671B, but it's not on Realtek's website. Instead the manual points you to:
https://www.mytechkey.com/pages/driver
4.Bluetooth 5.0 Dongle
Driver Link:
https://www.dropbox.com/s/gwo9lz777i82f70/BT5.0%20Driver.zip?dl=0
Hope that helps someone.
https://github.com/peteristhegreat/drivers-backup/releases/tag/1.0
Direct link
https://github.com/peteristhegreat/drivers-backup/releases/download/1.0/BT5.0.Driver.zip
Adding visibility to @carkrueger 's comment below
If you look here: https://www.catalog.update.microsoft.com/Search.aspx?q=realtek+bluetooth+1.6.1015 You will find now: 1.6.1015.3014 from 11.01.2021
Direct download link: http://download.windowsupdate.com/c/msdownload/update/driver/drvs/2021/02/0d13721d-7aa7-47cf-887a-f53bcd228a5e_04c173bad44cec04d528d260392958dc6e5bcec3.cab
for backup purposes: h**ps://web.archive.org/web/20210216175344/http://download.windowsupdate.com/c/msdownload/update/driver/drvs/2021/02/0d13721d-7aa7-47cf-887a-f53bcd228a5e_04c173bad44cec04d528d260392958dc6e5bcec3.cab
Direct download and the popup window for 1.6.1015.3014 didn't initially work. I ended up needing to right click the link and select Save target as.
For it to work for me on Windows 10, I unzipped the cab file into a folder and then used Device Manager to look at that folder. Worked like a charm.
So I can use some help here. I bought a Hakimonoe long range 5.4 Bluetooth dongle Amazon link . I own two bluetooth earbuds. First is a Tozo NC9 and the other are Earfun Air pro 4. Now the tozo will connect to the dongle no mater what driver I have installed. The Air pro 4 seem to really (really) picky. Right now I am using the Realtek driver 18.4017.2411.1911, and they connect fine. But if I try to use 1.9.1051.3013, 3014, 3015 I get an error message about "Windows rejected a legacy connection from your Bluetooth device (70:5a:6f:6b:3c:4b) because the system is configured to not allow legacy connections by your system administrator." it is like if the dongle thinks it is 5.4, the ear joys stop connecting. 5.3 or generic is fine.
any ideas?