Dear Colleague,

In ArcMap, methods are provided to solve this problem. I suggest you read the article of Esri company, the link of which is below. Reading other articles will also be useful.

https://desktop.arcgis.com/en/arcmap/latest/manage-data/editing-fundamentals/removing-slivers-or-gaps-between-polygons.htm

https://gis.stackexchange.com/questions/424907/workflow-to-remove-gaps-between-polygons

https://community.esri.com/t5/arcgis-pro-questions/close-gaps-between-polygons/td-p/711676

best wishes.

You can use auto fill polygon tool to fill gaps and then merge with adjacent polygon. If you are looking for single click solution then it is not possible because you have multiple features so you have to do a bit efforts.

And second solution is create topology and remove all gaps errors.

If you need any future details. Send me a message!

A related problem ( inverse),but once you have the centerlines of the gaps, you can generate new polygons. - "I am trying to find a tool to create a skeleton of a large vector dataset using QGIS and its bundle. It should be directly programmatically callable through Python or commandline (QGIS, GRASS, OGR etc. are all okay). ...The target is a large thin polygon with holes representing street areas and I need to obtain an approximation of the road network via skeletonization. https://gis.stackexchange.com/questions/171145/skeletonize-vectors-in-qgis-python