As it is stated on the official site of eTwinning "It is always good to inform parents about the work in eTwinning as in that way you let them know what you are doing with the students."
Consequently, we think it is a good practice to share parental consent forms with the parents of our students making them formally aware of their children's participation.
Etwinning has not got a specific form that we can all use. You should find ready made forms for this purpose if you google about it on your native language.
My advice. Every country must have a form like that. However, the one available in Greece didn't reflect the way my students will participate. So, I downloaded it and adapted it to saying "I allow for my kid to participate in the Easter Cards Project and the upload of the material he/she will produce".
If you need more information you can check this Etwinnng site Click here
As an indication that you received the forms from the parents, you can upload a photo (remember to hide any names or personal details on the forms).