Well I am not whether it is correct to use this phrase "Thankfully or not" in a sentence please suggest.
Thankfully or not we are not invested with divine power.
Here is an excerpt from the entry for the word 'thankfully' at the site
The use of thankfully to mean 'fortunately', 'let us be thankful (that)', is still disliked by many people, although it is becoming accepted. In this sense it is separated from the rest of the sentence by a comma. Thankfully they went to their grandfather's that day means that they went there full of gratitude; Thankfully, they went to their grandfather's that day means that it was fortunate that they did so; They went to their grandfather's, thankfully, that day means it was fortunate that they went on that particular day.
I am one of those 'many people' who 'still dislike' this usage. You must decide if you are also one. The issue is one of usage. 'Thankfully' is an adverb meaning 'in a thankful manner'. Your example sentence uses it to mean 'fortunately', as in the paragraph above.
As an adverb it would be used in a sentence such as this: 'The teacher spoke thankfully of the excellent students she had been blessed with.'
I hope this is helpful,
I have always had problems using thankfully as fortunately but I've been thinking that it's beacuse of me not being a native speaker. Also I am hearing people use it a lot. Thanks for the enlightening answer.