How to upgrade Node from vulnerable 12.x version? (DigitalOcean 1-click stack)

Tried to upgrade Node version used by Strapi because version 12 is flagged as High risk in Sqreen service.

  • Installed version 14 and made current via NVM on both root and strapi usr
  • Changed package.json to {engine: >=14.x.x <15.x.x
  • used yarn build --clean (during pm2 strap service stopped)
  • checked config and cache folders, server json, .env files

Could not find any instruction how to do so except general notice upgrade button will show under settings/application for strapi or node

What am I missing? is there some extra hidden config file or db record?