Ember.js 4.4 classic template syntax

I would like to update a project built in Ember 3.28 without Octane to version 4.4.

I tried using ember-cli-update to change version and now all sorts of errors are thrown, such as template properties that must be used with @ and curly brackets components no longer supported...

I am new to Ember and I haven't understood if it is still possible to use the classic syntax on 4.4, if so, how can I continue to use the classic syntax? Especially on templates.

Thank you!