You will need the Full Read Financial permission to perform this action.
There are two ways to download multiple giving statements at once depending. You can either download them for the entire church in one shot, or you can create a report query to target specifically the ones you want.
Generate for Entire Church
Click on "Contributions > Transactions" in the left hand navigation and then on "Generate Giving Statements" from the drop down at the top.
A pop up will appear similar to the one you see when downloading an individual statement. Complete the options and then click on button at the bottom.
Important: depending on how many transactions there are, this could take a while.
Generating Based on Criteria
You will need the Reporting permission to perform this action. Navigate to the People Query Builder and construct a query which matches the people you are interested in downloading giving statements for. Once done, click on "Giving statement" in the actions menu.
A pop up will appear where you can specify the details for the giving statements. Once finished, click on "Download" to download the giving statements for all the people returned in the query. If you're interested in seeing who they are, click on the "who?" link at the top of the pop up.
Important: this will generate giving statements ONLY for people who have a profile in the system. If you are interested in including guest transactions as well (i.e. unmatched), please see previous section named "Generate for Entire Church."