I put the translation in the folder ../wp-content/plugins/improve-my-city/languages
I tried the following names settings for the file.
Improve My City-pt_BR.mo
Improve My City-pt_BR.po
and
Improve My City-pt_br.mo
Improve My City-pt_br.po
and
pt_BR.mo
pt_BR.po
not one of those ways worked…
Translation by the Poedit, as you can see in print https://prntscr.com/bjmb32
What should be the filename to finally work, if you are interested after completing can make it available to you.