How can I get 1 GB data subscription?

I presume you are referring to the upload space? 

Please check our pricing page to learn more the difference of each subscription plan and their account limits: https://www.jotform.com/pricing 

I see your account was set to overlimit, I have recalculated your monthly usage and your account should now be fixed and active again.

The subscription plan fitting for you depends on what you need. You can have a better view of your limits by logging in to your account and navigating to your Account->Usage page. Here are some brief description of each limit:

Monthly Total Submissions: The number of submissions you can receive monthly, this resets every 1st day of the month.

Monthly Payment Submissions: If your form is using a payment integration, this is the total number of completed payment submissions you can receive monthly. This resets every 1st day of the month.

Monthly Form Views: This is the number of views you are allowed to have in your forms. To learn more about this, please check this guide: https://www.jotform.com/help/355-Form-View-Limits-What-is-it-all-about 

Upload Space: If your form has file upload fields on them, then this is the total file upload space you are allowed to have. This is fixed and does not reset.

Submission Storage: This is the total submissions you can STORE in your account. This is also fixed and does not reset. 

The limits changes if you upgrade or downgrade, depending on what subscription plan you are at.

I hope that helps.