Giving notice of rebellion on Instagram? (9)

I believe the answer is:

apprising

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'giving notice' is the definition.
('apprise' can be a synonym of 'give notice')

'rebellion on instagram?' is the wordplay.
'rebellion' becomes 'rising' (synonyms).
'on' means one lot of letters go next to another.
'instagram?' becomes 'app' (I can't justify this - if you can you should believe this answer much more).
'rising' put after 'app' is 'APPRISING'.

'of' is the link.

Can you help me to learn more?

(Another definition for apprising that I've seen is " Informing".)

I've seen this clue in The Guardian.

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