When a toilet leaks around the base every time it is flushed, that typically means there is an issue with the flange wax ring seal. The drain pipe for the toilet comes up through the floor and connects to a circular plumbing fitting called a toilet flange that is secured to the floor. This flange is what the toilet mounts to with the toilet bolts (closet bolts).
The gap between the flange and the porcelain outlet of the toilet is traditionally sealed with a wax ring donut-shaped gasket. This keeps all the waste water from leaking as the toilet is flushed. The perimeter of the toilet base is usually sealed to the tile with caulking to prevent dirt from getting up under the toilet where it can’t be cleaned. Unfortunately, when you have a toilet that is leaking around the base, that means the wax ring seal is compromised.