# How to add reaction in Flutter?

**URL:** <https://community.sendbird.com/t/how-to-add-reaction-in-flutter/6247>\
**Category:** Flutter\
**Created:** [December 30, 2022, 5:59am UTC](https://community.sendbird.com/t/how-to-add-reaction-in-flutter/6247 "2022-12-30T05:59:08Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dream7special](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/dream7special/32/2178_2.png) [@dream7special](https://community.sendbird.com/u/dream7special)\
**Post date:** [December 30, 2022, 5:59am UTC](https://community.sendbird.com/t/how-to-add-reaction-in-flutter/6247/1 "2022-12-30T05:59:08Z")

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I tried several times to use Sandbird’s reaction function.  
I tried to update the reaction using ‘applyReactionEvent’ in the message function to add a reaction, but it is not updated on the sendbird server and only applied to the chat room.  
And also i tried to use ‘addReaction’ of channel function, but i get error message that is ‘Unhandled Exception: type ‘Null’ is not a subtype of type ‘int’ in type cast’. and check in ‘package:sendbird\_sdk/features/reaction/reaction\_event.g.dart’, the problem occurs because there is no ‘updated\_at’ value.  
How can I solve this?

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**Author:** ![Nguy\_n\_D\_c\_Thu\_n](https://sea2.discourse-cdn.com/flex020/user_avatar/community.sendbird.com/nguy_n_d_c_thu_n/32/4426_2.png) [@Nguy\_n\_D\_c\_Thu\_n](https://community.sendbird.com/u/Nguy_n_D_c_Thu_n)\
**Post date:** [August 18, 2023, 3:10am UTC](https://community.sendbird.com/t/how-to-add-reaction-in-flutter/6247/2 "2023-08-18T03:10:44Z")

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Same issue here, nearly a year pass and no fix for this?