In a first step please check your filter settings.
If you still can't see the desired platform although you chose the correct settings that can normally have the following two reasons:
1. you aren't a member of the group which has access to the platform or
2. your group doesn't have access to the platform.
In this case please contact your admin so you or your group gets access.
If none of the above was helpful to you please contact our support at firstname.lastname@example.org.