Invoking a OAuth enabled consumption logic app from Web API - azure-logic-apps

Question

My consumption logic app is OAuth enabled which means the trigger to the logic app requires a bearer token.
Im using Managed identities for the AD authentication. I have Managed Identity enabled on my AppService and on my Logic App. I have also assigned the appropriate roles for the AppService Service Principal to the Logic App
$appServiceIdentity = Get-AzADServicePrincipal -DisplayName $(appservicename) | select -ExpandProperty Id
$isAppServiceInLogicAppContributor = (Get-AzRoleAssignment -ObjectId $appServiceIdentity -RoleDefinitionName "Contributor" -Scope "/subscriptions/$(azureSubscriptionId)/resourceGroups/$(resourceGroupName)/providers/Microsoft.Logic/workflows/$(thelogicappName)")
if (!$isAppServiceInLogicAppContributor)
{
Write-Host "Assigning App service to Logic App Contributor..."
New-AzRoleAssignment -ObjectId $appServiceIdentity -RoleDefinitionName "Contributor" -Scope "/subscriptions/$(azureSubscriptionId)/resourceGroups/$(resourceGroupName)/providers/Microsoft.Logic/workflows/$(thelogicappName)"
}
The roles are assigned correctly and visible on the Azure portal as well
The Logic App ARM template has the OAuth settings for the triggers
"triggers": {
"openAuthenticationPolicies": {
"policies": {
"endpoint-oauth-policy": {
"type": "AAD",
"claims": [
{
"name": "iss",
"value": "[concat('https://sts.windows.net/', variables('tenantId'), '/')]"
},
{
"name": "aud",
"value": "https://management.core.windows.net/"
}
]
}
}
},
The Web API uses DefaultAzureCredential library to fetch the token. Im not specifying any environment variables for the Identity check. The code for fetching the token looks like below
var tokenClient = new DefaultAzureCredential();
var token = tokenClient.GetToken("https://management.azure.com/.default");
However I get HTTP 401 with the tokens. The token contains the aud and issuer with correct values.