Send Message button – To and Subject

Hi. I have read previous knowledge base entries but I cannot crack my issue.

I have a classifieds website, and I want to add a ‘SEND MESSAGE’ button on an Advert page which automatically populates the TO address with the author of the post/Ad and the SUBJECT too ideally with enter the Ad title or the current URL

My slug is [front-end-pm] … I think!

On my classifieds site WP-admin settings, there is a box entitled Single Ad page layout with previous entries WHICH WORK – for example ..

Visit Advertiser’s portfolio other items :
<a href="$bp_user_listings_url">$bp_user_listings_url</a>.
THIS WORKS FINE

so, For the ‘Send Message’ button, I tried to insert Under the line above :-

<a href="'.get_bloginfo("wpurl").'/front-end-pm/?fepaction=newmessage">New Message</a>

I get the ‘NEW MESSAGE’ button, but when I click it, it redirects me to :-
http://www.finditswapit.com/awpcp/show-ad/'.get_bloginfo(
and errors with Page cannot be displayed

I’ve tried adding different variations like

<a href="'.get_bloginfo("wpurl").'/front-end-pm/?fepaction=newmessage&to=' . the_author_meta("user_login"). '">Send Message</a>

= same thing

Also tried
<a href="<?php get_bloginfo("wpurl");?>/front-end-pm/?fepaction=newmessage&to=<?php the_author_meta("user_login");?>">Send Message</a>

= same thing

Any ideas anyone?
I am running WordPress 4.4.2 with Front End PM 3.3 on Linux Ubuntu 14.04

Thanks
Russ
webdev71

https://ww.wp.xz.cn/plugins/front-end-pm/