Fast way to find out the ISSN number of Publications
To get the ISSN of a paper by using the paper's DOI, try CrossRef's API. Specifically, use the URL https://api.crossref.org/works/ and add the DOI to it.

For example, if the DOI is 10.1177/0047117819856397,
then use the URL https://api.crossref.org/works/10.1177/0047117819856397

There is a branch called "ISSN" in that JSON-file. If the output looks confusing to you, copy-paste it into a 'JSON beautifier'.

(However, note that you cannot find the Impact Factor of the journal using this approach; as far as I know, there is no API for accessing an Impact Factor by using the ISSN as a key. Also see "Where can I find the Impact Factor for a given journal?")