I don’t know how i can do a timelapse in krita 
Hello @Lorena_Parlote_Darti, and welcome to the forum!
If you want to do it with Krita’s own means, you have to “activate” the Recorder Docker, which is found via the menu “Settings” → “Dockers”, just set the hook in its checkbox and it will show up in Krita’s interface.
Then you have to set it up to your liking and can begin to record your painting sessions. At the end, when you want to make a movie from the screenshots made, you have to click on the export button and can render it to a video.
In the case that you may have seen older videos about rendering videos with Krita, you do not need to install FFmpeg separately, Krita has it since version 5.2.0 implemented. Only if you want to go for extreme resolutions, which won’t bring any benefits with currently available display technologies, you would need an external FFmpeg which offers the needed proprietary codecs for that. But up to resolutions of 4k, you are fine with Krita’s own means.
By the way, if you are using an Android device, it is not as easy to render videos as with the desktop versions, as Krita for Android cannot render videos due to the restrictions placed on Android by Google. You are therefore reliant on either rendering the videos created there on your desktop computer with Krita, asking a friend to do this, or finding one of the few Android video editors that compiles your video from the individual screenshots. This is a little more complicated than on a PC, but it can definitely be done in a roundabout way, and many people do just that using Android.
Here you’ll find the chapter about the recorder docker in Krita’s manual:
Michelist