Type F1 alt+x, where F1 means the letter F key followed by the 1 key, not Function key 1. U+00F1 is the Unicode value of ñ. In general to type in a character by its Unicode value, type in the hex value and then alt+x. E.g., to type in math italic a, type 1D44E alt+x , which gives 𝑎.
Murray
