How many shots are executed when using the IBMQJobManager?

When using execute in qiskit, you can specify how many shots you want done for a circuit in the following way:

#for a defined circuit and backend
job = execute(circuit, backend, shots=___)

where you fill in the blank with some number between 1 and 8192, the min and max shots you can execute on any backend. If you want to run one circuit, I would use execute.

If you want to run many circuits at once, then I would use IBMQJobManager. You first have to put the circuits in a list and transpile them to your backend, then run them using the method IBMQJobManager().run(). You can also specify the number of shots for each job as shown:

#for a defined list of circuits and backend
circuits = transpile(circuit, backend)
job = IBMQJobManager().run(circuits, backend, shots = ___)

where the range for the possible number of shots is the same as that for execute. More information about IBMQJobManager can be found here: https://qiskit.org/documentation/stubs/qiskit.providers.ibmq.managed.IBMQJobManager.html#qiskit.providers.ibmq.managed.IBMQJobManager

Also, the default number of shots on any job run on an IBMQ backend is 1024.