안녕하세요 flask aws p.284실습 중 다음과 같은 에러가 뜹니다. ㅠㅠ

ubuntu@ip-172-26-7-101:~$ sudo apt install python3-venv
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package python3-venv is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'python3-venv' has no installation candidate

sudo apt install python3-venv 명령어를 실행했을 때.. 이런 에러가 뜨는데 어떻게 해결할 수 있을까요? ㅠㅠ