My app has frames from third party code where I do not have access to the debug files for symbolication. These frames appear at the top of my stack trace and I would like Sentry to not use them for grouping purposes. In the Sentry Ui these frames show as Unknown

You can use Sentry's Stack Trace rules feature change the behavior of how Sentry groups by the stack trace. If all the top frames are unknown (indicating an empty stack.function in the exception stack trace of the JSON), you can set a stack trace rule to find the first frame that has a valid stack.function value. Then you can set all the frames above the found frame out of grouping considerations.

An example stack trace rule could be - stack.function:"?*" ^-group. This rule will start from the top of the stack and match with the first frame that has a stack.function value of at least 1 character. Then, it will mark all the frames above it (signified by the ^) out of grouping consideration (signified by the -group).