Background Information:
I'm trying to make a patient login to my system and upon the login I want them to provide consent and get access token to follow up the R4 requests.
Actual Problem:
I've been facing issue that the registered app is not being recognized instead it is showing as Unknown App.
Description: I developed an application with these configurations from this link: [EVERYTHING IS IN TESTING ENV]


And upon referring to the documentation, I formed this URL that takes me to the login page and provides the consent:
URL:
https://authorization.cerner.com/tenants/ec2458f2-1e24-41c8-b71b-0e701af7583d/protocols/oauth2/profiles/smart-v1/personas/provider/authorize
?client_id=d5d3c9ff-23bc-433f-b8ca-f260a1c140ce
&response_type=code
&redirect_uri=http://localhost:5000/callback/cerner
&scope=user/Observation.read user/MedicationHistory.read
&aud=https://fhir-ehr-code.cerner.com/r4/ec2458f2-1e24-41c8-b71b-0e701af7583d/
&state=a4c16a46-2c46-482c-8d66-4cc4a2990bda
Upon redirection following happens:
1: Login Page

2: Unknow app issue,

3: Upon Proceed Anyway, I get still the unknown app issue

4: Callback gives the code

5: But upon using the code for /token to get the access_token I'm getting this error:

Upon opening the link, it shows the same error of unknow app:

Expected Result: access_token and other fields
Actual Result: "error": “invalid_client”
What am I doing wrong here, I saw the similar issue with a lot of issues but nothing seems to work out perfectly, even the solution regarding the TXT records.
I'm unable to get that what value and target do I put in the TXT records.
If the issue is something else or my flow is wrong, then kindly help me with it.
Thanks