I am having trouble finding the monthly option when choosing a plan. I do not want to pay a year upfront.
Are you referring to the different Square Online Store upgrade options, @elloheimclark?
If so, you'll simply log into your Square Dashboard, then click on your Online Store button. Once you're there, you'll see the word Upgrade in the top right-hand corner. Click this to view your upgrade options.

On the next page, you'll select a plan by clicking the Select Plan button. Clicking there will take you to review your choice, and here is where you will have the chance to select a term length (1 month vs 1 year).

Please let me know if this isn't what you were looking for!
Square Community