Please share the location of the bus terminal in Phnom Penh?
That's right. There is no single terminal.
I used giant ibis
There may be several of them here, as each carrier has its own platform with a ticket office
There are also aggregators. There are different companies, prices, and bus stations. For example, Bookmybus or 12th. Or at the hotel, you can buy a ticket at the reception, and they will pick you up from the hotel and take you to the bus. But it will be a bit more expensive.