simple todo with oak mysql deno-sqlbuilder for heroku

this is example of simple todo :
in backed it use deno oak sqlbuilder and mysql as database server
in frontend i use a static site made with vuejs and js, code of frontend come from foalts tuto with little modification
I use deno deploy service to deploy this web app for free
I use freedb.tech as free mysql server provider
then I can deploy real web site for free, if we don't need custom domaine name or filestore sys .