Add a custom text with tax / legal terms on invoices

We would like to add a text (e.g. with taxation terms) on our invoices as the very last paragraph directly before the signature. Please advise.

You can easily add such a text at the described position. Please go to:
Overview => Settings => Wording and Phrases

Search for the following string “S_INVOICE_APPENDIX”. Edit this phrase and enter your text.
Please take a look at the position of the new item in the image below.

If you want to add a header or footer text, or payment terms just below the invoice table, you have the following options:

Please open the settings for participant registration here:
Overview => Settings => Main Settings for Participant Registration

To add payment terms and conditions or legal information relating to payments, add another line of text directly beneath the table showing the items and prices on the invoice.
Enter additional text in the field "Legal Clause for Invoices".

For the next two items, turn on the Expert Settings toggle in the lower navigation bar.
The toggle is labeled "Expert Settings Disabled" until activated.

You can enter further information as text in the field "Extra header for invoices (optional)" which will be put at the very top of the invoice, and in the field "Extra footer for the invoices (optional)", which will appear at the bottom of the page.

The positions of these items are pictured in the image below.