Sometimes, it is convenient and acceptable to have your crew members review some topics on their own. For those times and topics, use Self-guided Training.
Have your crew use their smartphones to scan the topic QR codes to open their Trainee's Portal. On it, they can view the topic material, sign (if needed), and submit it for your records. For those who are remote, send them the topic link. Want something more convenient? Use the Prompted Toolbox Training.