Hi, this project is unfortunately not very active and we haven't accommodated for updates in elasticsearch or kibana. I'm not the maintainer of this project but if you have a pull request that addresses the issue I'd be more than happy to look at it.

Memo to myself:
To extract scripted fields from exported kibana saved-object files, changing their data structure to the one used for dynamic fields:

jq '.[] | select(._type == "index-pattern")._source.fields | fromjson | reduce (.[] | select(.scripted == true)) as $i ({}; . += { ($i.name): { type: $i.type, script: { source: $i.script } } })' dashboards/dashboards.json

Note that the script field content still needs to be updated to use emit() as per docs. That's already done in #37

I have managed to "migrate" this to runtime fields within index-template some time ago that I plan to start using soon - I decided to use https://github.com/elastic/terraform-provider-elasticstack for that. Once I find some time I could share those snippets, if you like. I do remember there were some challenges with reformatting everything so that you can push the json properly but still maintain some readability of .tf files.