accessing payload data stored by delimited payload token filter through painless script

I want to use stored payload for scoring instead of bm25.

I used delimited payload token filter to store payload value per term, and payload data are saved well when checking through term_vector API.

I tried to access payload value by script score function, but past examples are written in groovy which are no longer supported as script_lang.

is there any way to access payload value through painless script?

Thanks in advance