Help, toilet leak

[Slamilton]

I just took out my new to me Swift 154bh and there is a leak at the back of the toilet. The unit was winterized when I bought so I couldn't check everything. I filled the water tank and then when I turned on the water pump the water started spraying our of the back connection. I have attached a picture of the fitting. There doesn't seem to be a seal or anything. I can easily connect it but when I turn the pump on it leaks. Is there something I can do to fix? It seems like it should be simple. It just seems the connection is not great or is missing the seal. Any suggestions? The picture shows it unconnected and I can easily put it together but it still leaks. Also, I want to go out this weekend so is there a shut off valve for just the toilet so I can use the sink still? I couldn't find one. Thanks.

[DMRGMC]

I put a 1/2" shark bite shut off in line between the floor and the female coupling. Because the shut off handle on the shark bite was so long I removed the rubber grip, cut off part to shorten the handle, filed the edge of the cut, then cut to length and replaced the rubber to the handle, just for asthetics. Works great.