importing in template gives "TemplateSyntaxError: Encountered unknown tag 'do'."

[kafeenstra]

I'm fairly new to home assistant, and particularly to templates and jinja.

I'm trying to use the cheapest_energy_hours.jinja integration from my custom_templates/. I've tried this via a helper template sensor (as instructed in e.g. dishwasher_overnight) but that reads 'Unavailable'.

Then, I tried playing around in the developer-tools\template sandbox, but even only adding the import statement only gives me:

TemplateSyntaxError: Encountered unknown tag 'do'. Jinja was looking for the following tags: 'endmacro'. The innermost block that needs to be closed is 'macro'.

It seems I may be doing something wrong, but I have no clue where to look or where to start.

[TheFes]

Which version of Home Assistant are you using?
This was added in in May 2025, so if you are getting this error my first guess is that you are still using a HA version prior to that.

[kafeenstra]

Ah, that explains. I'm on 2025.4.4

[TheFes]

In that case you can either update, or use a version prior to 7.0.0

https://github.com/TheFes/cheapest-energy-hours/releases/tag/v6.0.5 would be the last version supported in 2.25.4.4