Very often, both affiliations are given. E.g., the old affiliation is given in the header lines of the paper, and a footnote is added to one of the authors like "New address: ..." However, in your case, when all authors have changed their affiliation, this may not work. I would recommend to add a footnote to the title of the paper or to add a sentence to the acknowledgements, saying that "This research was conducted at ..." In any case, the redactor of the journal should give advice who to handle this case.

Old because the credit goes to the institution that funded the research

You must provide former affiliation in the header line; use a footnote to provide the current affiliation.