Amazon (AMZN) is now limiting the number of new grocery customers it is accepting, with an invitation-only process that will help it prioritize orders for its existing customers during the coronavirus pandemic.

According to the company, it is temporarily asking new Amazon Fresh and Whole Foods Market delivery and pickup customers to sign up for an invitation to use its online grocery service because it is seeing increasing capacity each week.

The company said it is releasing new delivery windows each day and will invite new customers when there is availability to shop. The wait-list started on Monday while the company works to add more capacity each week as demand for groceries grows.

Amazon has also increased the number of Whole Foods Market stores that now offer grocery pickup to 150 locations, up from the 80 stores that previously offered the service. Amazon also said it will increase the number of stores further in the coming weeks.

The e-commerce giant has hired 100,000 employees in recent weeks to help with the added demand it is experiencing during the COVID-19 pandemic. Some of these workers are helping with grocery demand with plans to add 75,000 more workers to help facilitate Amazon orders further.

Amazon also said that some of its Whole Foods Market stores will now have reduced hours so employees can focus on fulfilling online grocery orders quicker.

“While we have increased order capacity by more than 60 percent due to COVID-19, we still expect the combination of restricted capacity due to social distancing and customer demand will continue to make finding available delivery windows challenging for customers,” Amazon said in a statement.

“To help, in the coming weeks, we will launch a new feature that will allow customers to secure time to shop. This feature will give delivery customers a virtual “place in line” and will allow us to distribute the delivery windows on a first come, first served basis. Simultaneously, we will continue to add capacity as swiftly as possible.”

Shares of Amazon stock were up 4.62% as of 12:00 p.m. EDT on Monday.

An Amazon delivery truck drives in downtown Los Angeles on May 13, 2014. Reuters/Mike Blake