Running the demo with fitbit

[hannahburkhardt]

Hello,
I ran the demo at the bottom of the page at tinyurl.com/omhonfhir
I do not currently use Google Fit, but I have a Fitbit account with a developer account and API key.
In shimmer-resource-server.env, I have updated OPENMHEALTH_SHIM_FITBIT_CLIENT_ID and OPENMHEALTH_SHIM_FITBIT_CLIENT_SECRET to match my information. I have also updated the callback URL in my dev.fitbit.com app settings to be http://localhost:8888/mdata
I also tried http://127.0.0.1:8888/mdata (for both dev.fitbit.com and shimmer-resource-server.env)
However, after selecting Fitbit from the simulated EHR and authenticating, I am getting the following error:

The app you're trying to connect did not provide valid information to Fitbit. Please report this issue to them.

Developer information: invalid_request - Invalid redirect_uri parameter value

Do you have any thoughts on what steps I might take to address the problem?
Thanks!