The config.transactions cloner for resharding should take the aggregation pipeline from SERVER-49898, run it against a particular donor, and update the config.transactions entries on itself (a recipient).

• Serialize the aggregation pipeline from createConfigTxnCloningPipelineForResharding() using Pipeline::serializeToBson() and use the serialized form to create an AggregationRequest.
• Add the necessary read concern and hint to the AggregationRequest.
• Run the aggregate command on the remote donor. See the description of SERVER-49893 for some ideas on the options for this.
• Follow the procedure for updating the entries (or inserting new entries) in the config.transaction table described in the design document.