Hi @michael_oluwaseyi
You need to update your composer first then composer update.
You can update your composer using following command:
composer require magento/product-community-edition=2.3.2 --no-update composer update
You can change 2.3.2 with your version for which magento version you want to upgrade.
Thanks it worked.. How do i accept as solution?
HI @michael_oluwaseyi
Good to know that it helps you!
I think only post owner @taragurung or Moderator can accept as a solution.