Note: This comes with no guarante this repo is for educational purposes only not an official Pantheon repo
Use the following direct link to create a new site on Pantheon:
https://dashboard.pantheon.io/sites/create?upstream_id=76da4192-1d0f-480b-b8f4-accbeeae458e
Avoid confusion by moving your site to an empty upstream:
terminus site:upstream:set <sitename> empty
composer update drupal/core --with-dependencies
composer prepare-for-pantheon
composer install --no-dev
lando init --source=pantheon
Edit .lando.yml and add the line at the bottom. Change the framework to drupal 9
config:
framework: drupal9
services:
database:
type: mariadb:10.4
Issue lando rebuild, start then pull
lando rebuild
lando start
lando pull
lando drush cr