Argument of type 'ValueTask<string?>' cannot be used for parameter 'value' of type 'ValueTask<string>' in 'ConfiguredCall SubstituteExtensions.Returns<ValueTask<string>>(ValueTask<string> value, ValueTask<string> returnThis, params ValueTask<string>[] returnThese)' due to differences in the nullability of reference types.

Argument of type 'ValueTask<string?>' cannot be used for parameter 'value' of type 'ValueTask<string>' in 'ConfiguredCall SubstituteExtensions.Returns<ValueTask<string>>(ValueTask<string> value, ValueTask<string> returnThis, params ValueTask<string>[] returnThese)' due to differences in the nullability of reference types.

Argument of type 'Task<AuthorizationHeaders>' cannot be used for parameter 'task' of type 'Task<AuthorizationHeaders?>' in 'ValueTask<AuthorizationHeaders?>.ValueTask(Task<AuthorizationHeaders?> task)' due to differences in the nullability of reference types.

Argument of type 'Task<AuthorizationHeaders>' cannot be used for parameter 'task' of type 'Task<AuthorizationHeaders?>' in 'ValueTask<AuthorizationHeaders?>.ValueTask(Task<AuthorizationHeaders?> task)' due to differences in the nullability of reference types.

This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.

Argument of type 'ValueTask<string?>' cannot be used for parameter 'value' of type 'ValueTask<string>' in 'ConfiguredCall SubstituteExtensions.Returns<ValueTask<string>>(ValueTask<string> value, ValueTask<string> returnThis, params ValueTask<string>[] returnThese)' due to differences in the nullability of reference types.

Argument of type 'ValueTask<string?>' cannot be used for parameter 'value' of type 'ValueTask<string>' in 'ConfiguredCall SubstituteExtensions.Returns<ValueTask<string>>(ValueTask<string> value, ValueTask<string> returnThis, params ValueTask<string>[] returnThese)' due to differences in the nullability of reference types.

Argument of type 'Task<AuthorizationHeaders>' cannot be used for parameter 'task' of type 'Task<AuthorizationHeaders?>' in 'ValueTask<AuthorizationHeaders?>.ValueTask(Task<AuthorizationHeaders?> task)' due to differences in the nullability of reference types.

Argument of type 'Task<AuthorizationHeaders>' cannot be used for parameter 'task' of type 'Task<AuthorizationHeaders?>' in 'ValueTask<AuthorizationHeaders?>.ValueTask(Task<AuthorizationHeaders?> task)' due to differences in the nullability of reference types.