Up to 20 channels (sessions) simultaneously, but it depends on the payment plan you have chosen and how many sessions you paid for when purchasing a package (subscription).
1. With the Prepaid payment scheme, 2 authorized sessions (channels) are set by default.
With such a selection of allowed sessions, you can watch 2 channels at the same time. If you want to watch, for example, 3 or 4 channels at the same time, you need to set 4 authorized sessions, 5-6 channels - 6 authorized sessions, etc.
If you bought a package and forgot to change the number of allowed sessions, you need to stop the package through the service support or wait for it to end, change the number of allowed sessions in the settings of your personal account, save and buy the package again, the price of a package with a larger number of devices will be more expensive, for example, a package for 4 simultaneous sessions (channels) costs twice as much as for 2 sessions (for 6 it is 3 times as much, for 8 it is 4 times, etc.).
Or, without stopping the package, add a subuser and buy a package for him, from the playlist of this subuser, you can watch another 2 channels. This option is more convenient - different packages can be connected, for example, a package for TV in the nursery and packages with channels for adults or sports for your TVs).
2. With the Time-based payment scheme, you can set up to 20 permitted sessions yourself, without contacting support.
Money for viewing will be charged for the fact of viewing, not for the number of sessions installed.