How to get rid of them?

I have been getting about 10 bugs every day from an upstairs bedroom. I think they are coming in the window seal. I got it sealed but they keep coming in. I had an exterminator come in but couldn’t find anything. So I got some bug killer spray from an exterminator store and got rid of them in one spray. The problem is the exterminator store is closed now and I don’t know where to get the bug killer spray. Does anyone know what they are using?