Please note you can also create all your invoices for all your jobs (even if these jobs concern different clients!) in just a click at the end of the month. See this article: https://help.lsp.expert/en/articles/723115-can-i-invoice-more-than-one-job-at-once-for-one-or-more-clients.

To create an invoice containing all the jobs for a client, you first have to select all the jobs for this client. You can do that by using the filter in the list of jobs to only see the jobs for this client in your list...

...Or you can click on the Jobs tab in the details of the client.
​

Whatever the option you choose, you can then select all the jobs that have to be invoiced and click on Actions > Create invoice(s).

You'll arrive in the invoice containing all the jobs you selected, where you can edit the details of the invoice, generate the PDF document (by clicking on Actions > Generate PDF), etc.

You first have to select all the jobs for the client. You can do that by using the filter in the list of jobs...

...Or you can click on the Jobs tab in every client.
​

Whatever the option you choose, you select the jobs to be invoiced and you click on the arrow > Invoice selected jobs. You'll arrive in the invoice containing all the jobs you selected, where you can edit the details of the invoice, generate the PDF document (by clicking on Actions > Generate PDF), etc.