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In a nutshell you will likely need to:
request a VPAT from the vendor.
if not already using the product or service, procure a test account or trial version to thoroughly vet the product or service interface for accessibility.
request a road map for anything not meeting the requirements.
You would formally submit your findings to the SU Accessibility committee for review and receive either approval/rejection/exception.
This is the list of past product requests https://su-jsm.atlassian.net/wiki/x/2B_ACQ . Perhaps there is an alternate service that has already been approved that you may use.
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