Plugin dev & upgrade

Hello. Can anybody help us with some problems while upgrading plugin for kibana?
Plugin we have developed for version 6.5 and 7.0-SNAPSHOT. It works ok in both version. Of course, there are some difference for server code, but they are not so significant.
Now, we are trying to start kibana with plugin for 7.2 version.
for kibana home
git checkout 7.2
nvm use v10.15.2
yarn es archive elasticsearch-7.2.0-darwin-x86_64.tar.gz -E path.data=../data5 --license oss
for plugin home
yarn kbn clean
yarn kbn bootstrap
yarn start --oss

And getting an error:
export const AppConstants = {
^^^^^^
SyntaxError: Unexpected token export

It seems, that it doesn't understand for standard token 'export'
Why, where is the problem?

Hi @undwood
Check this link it may help https://www.elastic.co/blog/kibana-plugin-api-changes-in-7-2

I didn't find info on this page.