You can use Krescue to flash the EMMC with the latest version or mainline ubuntu or previous versions if present on the online repository,
as eMMC images can only be packed with legacy kernel and uboot till now, only the latest image of mainline kernel versions of linux (for amlogic) allow you to pack eMMC,
If you been able to boot the mainline linux from the SD card, run the command sudo emmc-install and the firmware will be installed onto the eMMC.
thanks for your answer @Electr1. That what i got after run sudo emmc-install. What should i do next to upgrade Ubuntu. There is version 18.4 kernel 5.3 in SD card
Where is Ubuntu installed ?
If it is already in the eMMC the procedure is complete, you can remove the SD card and it will boot up from eMMC.
if you are going to update the system its a very tedious process, instead of doing so, just flash latest version of Mainline Ubuntu available from Krescue, and update the system.