When trying to convey the idea that something is being validated or supported, there are a variety of synonyms one can use instead of "give/lend/add credence to something." For example, you could describe it as being corroborated, confirmed, verified, substantiated, or authenticated. Similarly, it could be said to have been endorsed, approved, sanctioned, ratified, or authorized. Other options include bolstered, strengthened, reinforced, buttressed, or fortified. Regardless of the wording chosen, the underlying meaning is that something is receiving additional weight or validity from an outside source in order to lend it additional credibility.