you can find guest post sites by google search operators
Keyword “Submit Your Content”
Keyword “Suggest A Post”
Keyword “This Is A Guest Post By”
Keyword “This Post Was Written By”
Keyword “Want To Write For”
Keyword “Write For Us”
Keyword “Writers Wanted”
Keyword + Intext:” This Is A Paid Post”
Keyword + Intext:” This Is A Paid Review”
Keyword + Intext:” This Is A Sponsored Post”
Keyword + Intext:” This Is A Sponsored Review”
Keyword + Intext:” This Was A Paid Post”
Keyword + Intext:” This Was A Paid Review”
Keyword + Intext:” This Was A Sponsored Post”
Keyword + Intext:” This Was A Sponsored Review”
Keyword Inurl: “Guest Blogger”
Keyword Inurl: “Guest Post”
For e.g.
Online digital marketing course in Mohali "submit your content"