How to convert characters into ASCII code?

I guess you mean utf8ToInt, see the R manuals:

utf8ToInt("Hello")# [1]  72 101 108 108 111

Or, if you want a mapping of the letters to their codes:

sapply(strsplit("Hello", NULL)[[1L]], utf8ToInt)#  H   e   l   l   o # 72 101 108 108 111

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