PayPal / Stripe Checkout significantly slowes Pagespeed

do any of you also have the same Problem? when i activate my Checkout via Stripe and Paypal my Pagespeed just drops and those are slowing my Page down hard!
is there any way to fix this problem? here is my read-only: Webflow - Gleitzeit Tandemfliegen

also, does anyone know how to reduce “initial server response time” seems also poor here.

i was thinking of going via a 3rd party program just because of this and downgrade to a non-ecommerce plan…

Thanks for your help!