I may know some. You can try to ask bscpad or trustpad for this. Both were offering very good service at this moment to launch your launch pad but I prefer to use bscpad over trustpad as it has become a popular launch pad for BSC project. There are lots of project have been doing pre- sale and main sale through use bscpad's service.

I'm not sure about this but you can try to use unicrypto as well https://unicrypt.network/ I guess it's free but the result will be determined by how good your project. If your project has been gaining various exposure in the communities and it may help you to make presale or sale to be completed in short time.