This is actually no help.
for Germany there is an new Law: Legal changes will take effect on June 19, 2026 and September 27, 2026:
Mandatory electronic cancellation button and other changes to consumer law.
Details regarding the electronic cancellation function:
The cancellation function must be clearly labelled with "Cancel contract" or another equivalent, unambiguous phrase.
It must be continuously available on the online user interface throughout the cancellation period, prominently displayed, and easily accessible to the customer.
The customer must be able to easily enter their cancellation information (name, contract details, and the electronic communication method used to receive confirmation of receipt of the cancellation). A corresponding electronic input form should suffice in the absence of more specific regulations.
After entering their information, the customer must confirm their intended cancellation. A clearly legible confirmation function with "Confirm cancellation" or another equivalent, unambiguous phrase must be provided for this purpose.
The customer must receive confirmation of receipt.
Receipt is presumed if the customer sends the cancellation notice via the cancellation function before the end of this period.
you will find all the here [https://www.hwkno.de/artikel/fernabsatzvertraege-und-vertraege-ausserhalb-geschaeftsraeumen-76,0,12771.html]
You can find all the requirements of this law for online shops on this website. It's in German; Google Translate will surely translate it into English or Bengali?