'Do' and 'does' are both forms from the present indefinite tense from the verb 'to carry out.' Which just one you will use will mainly count on the sentence's topic. Their utilization is sort of equivalent, aside from 1 occasion where You need to use 'do' rather than 'does.' https://financefeeds.com/unlocking-non-dilutive-capital-colton-wandkes-guide-to-rd-tax-credits-and-grants-in-puerto-rico/