I looked around other posts and it says there should be "Sync" option to sync with iCloud, but I don't see it. I also looked at the mrc converter and I don't understand how the process works either.
1Password Version: 6.8.9
Extension Version: Not Provided
OS Version: 10.11.6
Sync Type: Not Provided
The standalone version of 1Password allows you to sync a standalone vault to iCloud.
The converter suite contains a script to help you extract (via your Mac) the Safari password stored in iCloud Keychain.
These two are entirely unrelated. Furthermore, iCloud is a storage platform for various Apple products and services, whereas iCloud Keychain is simply a data format that uses iCloud to store various Apple services passwords (and some other encryption or security-related data).
Neither 1Password nor the converter suite can provide two-way synchronization of iCloud Keychain data.
Which of these are you trying to accomplish?