How did I fix «System has not been booted with systemd as init system (PID 1). Can't operate.» for `mongodb-org-server`?

[dmitrii_fediuk]

«System has not been booted with systemd as init system (PID 1). Can't operate.» for `mongodb-org-server`

• askubuntu.com/questions/1298846
• stackoverflow.com/questions/30691665
• mongodb.com/community/forums/t/208987

[dmitrii_fediuk]

I have solved the problem by upgrading MongoDB from 4.2 to 6.