All of your invoices are available in the Order Details (All Orders). There, you will find the option to Export Order Documents.
You also have the option to download your invoices as an invoice summary. Just select the relevant time period and download.
This summary is accepted by tax advisors and by some tax authorities, so please make sure you check that it is suitable for your situation!
Note: We cannot offer you any tax advice, so please contact your tax advisor or local tax authority for any questions about taxes.