Avowed adverbs are provided in this article. The words listed here are commonly found along with the verb avowed in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb AVOWED.
boldly, candidly, clearly
distinctly, explicitly, expressly
fearlessly, formally, frankly
freely, frequently, honestly
openly, plainly, publicly
repeatedly, solemnly
Hope this word list had the avowed adverb you were looking for. In addition to adverbs used with avowed, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.