Look in the upper-right corner of Chrome and click on the three dots/menu icon circled in the screenshot below.
Select Settings.
Under Settings, click About Chrome.
See if Chrome updates in the center screen where circled above.
If it updates, reboot your computer and try again.
If you continue to have issues with your microphone/camera in Collaborate after trying these steps, please feel free to reach out to the Tech Support group at 515-965-7300 to further troubleshoot the issue.