Your MySQL data is not lost. The volume is still attached to your MySQL service with your data intact (~150 MB). Your workspace is currently on the Hobby plan but in an inactive state, so once you activate your subscription from your billing settings, you can redeploy the MySQL service and it will pick up the existing volume with all your data.

what cards do you accept? I'm from the Philippines and haveimited card options

We require a bank-issued credit card (Visa, Mastercard, etc.) for payment. Prepaid and virtual cards are not supported. You can add your card and activate your subscription from your billing settings, and your MySQL data will be waiting for you once you redeploy.

If i downgrade to free version, what will happen? i just need the data entries in database

The Free plan provides $1/month in usage credit and supports volumes up to 0.5 GB, so your ~150 MB MySQL volume would still be accessible. Your service would need to run in serverless mode (App Sleeping) on the Free plan, but you could connect and export your data. The simplest path is still to activate your Hobby subscription from your billing settings since it gives you more resources, but the Free plan would work if you just need to pull your data out.

how can i export the data in the database?

You can go to the Console tab of your database and run a dump, then download the dump file from the filebrowser under the terminal window.