Stop flushing and stop other fixtures known to feed the unit. More water can increase the overflow risk rather than clear the obstruction.
What the observation means
The pump's sound does not establish that wastewater is moving successfully. Do not assume another flush will provide the force needed.
A useful next step
Keep people away from contaminated water and arrange appropriate assistance. Describe the bowl level and whether the motor ran during the original event. Do not open the unit, reach into its outlet or add chemical unblocker to a full system.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.