How to use Hashtag Suggestions on Publer
To use hashtag suggestion in Publer:
Firstly you need to be on the Create page where you can see the #HASHTAGS button:
#HASHTAGS button is also found on the ALT text field, the follow-up comments and it can be used wherever the #Hashtags button is.

Once you are there you can click the #HASHTAGS button and search by typing:

The insights for these hashtags are info provided by Twitter as the other social accounts do not provide such insight.
There are 5 ways how the hashtags are generated (Besides manually typing it on search):
Text/caption (It will simply scan the text of the post):

Single or multi-photos (It will scan the image(s)):

GIF (It will scan the image (moving image)):

Video (It will scan the thumbnail of the video):

Links (It will scan the thumbnail plus the description and title of the link):

Updated on: 12/07/2022
Thank you!