Before you take any other actions, please discuss all possible dates for the first mentoring session directly with your partner. It is likely that your partner has availabilities apart from those shown in the platform and is more flexible than you think.
You have been specifically connected in the mentorship because we believe that the both of you fit very well together as mentoring partners. If access to IT on the mentee's side is a limitation, consider whether public PCs and WiFi spots could be a possibility. Examples include libraries, quiet cafes with WiFi or, where appropriate, family and friends of the mentee.
If none of this is an option for you, please contact our service team or your contact person in your company/ NGO.