Using date-holidays with rollup

[afuerstenau]

When I just add date-holidays to package.json I get this:
[!] Error: Unexpected token (Note that you need @rollup/plugin-json to import JSON files) node_modules/moment-timezone/data/packed/latest.json (2:10) 1: { 2: "version": "2021e", ^ 3: "zones": [ 4: "Africa/Abidjan|LMT GMT|g.8 0|01|-2ldXH.Q|48e5", Error: Unexpected token (Note that you need @rollup/plugin-json to import JSON files) at error (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:158:30) at Module.error (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:12354:16) at Module.tryParse (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:12757:25) at Module.setSource (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:12660:24) at ModuleLoader.addModuleSource (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:22138:20)

After some searching I added the @rollup/plugin-json plugin to the rollup-config. Now, I am getting the following error:
[!] Error: 'default' is not exported by node_modules/deepmerge/dist/cjs.js, imported by node_modules/date-holidays-parser/src/utils.js https://rollupjs.org/guide/en/#error-name-is-not-exported-by-module node_modules/date-holidays-parser/src/utils.js (5:7) 3: */ 4: 5: import deepmerge from 'deepmerge' ^ 6: 7: /** Error: 'default' is not exported by node_modules/deepmerge/dist/cjs.js, imported by node_modules/date-holidays-parser/src/utils.js at error (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:158:30) at Module.error (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:12354:16) at Module.traceVariable (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:12739:29) at ModuleScope.findVariable (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:11531:39) at FunctionScope.findVariable (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:6902:38) at ChildScope.findVariable (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:6902:38) at MemberExpression.bind (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:9124:49) at CallExpression.bind (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:4998:23) at CallExpression.bind (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:9368:15) at ReturnStatement.bind (/Users/afuerstenau/projects/kundenportal/node_modules/rollup/dist/shared/rollup.js:4998:23)

I tried to solve the issue by adding export-name to the config but I don't know what exactly to put into the export-name area.

Any help is appreciated.