Translation issue

Hi,
I’m using MyTickets 1.9.6 with WordPress 6.0. My Problem:
When showing the purchase page the numer of tickets is displayed as “1at17,00€”. Although I’m using german language it says “at” but it should be “zu”.
The same problem with the receipt: It says “1 ticket at …” but should be “1 Ticket zu …” and in the payment details it says “Amount due” which should be “Offener Betrag”.
Any idea where I find the settings for these translations?
Thanks
Chrissi