As per paragraph 28 of the Procedures and rules, the pairing of States for the review process should be carried out by a drawing of lots at the beginning of the review process. 

In line with operative paragraph six of resolution 10/1, the Secretariat convened two joint intersessional meetings of the working groups, held on 23 November and 14 December 2020 respectively (drawing and redraws meetings). The result of the drawings of lots is available here.