This is a paid asset, but now you can download Playmaker Free.
Detail this asset from Unity Asset Store: Original Link
Playmaker v1.9.1.p5 (Latest version)
“If possible, please buy the package to support the developer”
The top-rated visual scripting tool for Unity used in Hearthstone, INSIDE, Hollow Knight, The First Tree, Observation, Dreamfall Chapters and more: Project Showcase
Artists and Designers: Realize your creative vision without coding! Unlock the power of Unity.
Programmers: Add a powerful visual state machine editor to your toolbox. Interface with scripts or extend Playmaker with Custom Actions.
:: NEW Nested Prefab support in 2018.3+
:: NEW Integrated UI Actions and Events.
:: NEW Auto-Convert Variables in Actions.
:: NEW Performance improvements.
:: NEW Category Icons for Actions.
:: NEW Favorites and Recent Actions.
:: NEW New Action Attributes.
:: Build behaviors in an intuitive Graph View.
:: Drag-and-Drop Actions – no syntax errors!
:: Save time with Copy/Paste and Templates.
:: Access scripts and third party plugins.
:: Enjoy powerful runtime debugging:
:: Watch States, Variables, and Events.
:: Pause and Rewind time with Debug Flow.
:: Download Action Packs for popular plugins:
:: NGUI, 2DToolkit, Photon, iTween…
:: Extend Playmaker with Custom Actions.
:: Watch tutorials on our YouTube Channel.
:: Join an active online community.
More Info >>
NOTE: Alpha versions of Unity are not officially supported. We try to support beta versions of Unity when possible, but it is generally recommended that you use an official Unity release for maximum compatibility.