Custom variables

I want to store some value inside variable and want to use where ever I want, and want to update it in flow. next I want to use updated value of the variable. when I browse n8n docs, custom variables are available in selfhost Enterprise version. as this is very basic requirement, how to achieve this ?

Custom variables are only available in paid plans. Edit(Set) Fields node works fine for me – excludes API keys etc. from requests. As an alternative you can use n8n’s Data Tables, or a database of your own.