How to convert the unit of surface runoff from meter to cubic meter per second?

Hello all, I downloaded reanalysis-era5-land-monthly-means surface runoff data for my study region from with the following details:
"product_type": "monthly_averaged_reanalysis",
"variable": "surface_runoff",
"grid": [ 0.5, 0.5]
I want to compare the value of ERA5 surface runoff with observed data in my study region. Since the unit of surface runoff in the observational data is cubic meters per second and the unit of ERA5 surface runoff according to the documentation is meter, I want to ask how to convert ERA5 surface runoff (SOR) units to m3/s. The goal is to have the value of ERA5 monthly average surface runoff for each month in the m3/s unit.

Any advice is highly appreciated.
Best regards