No confirmation message, profile is not displayed, etc...

Hi, I was playing around with this plugin for some 3 days, getting frustrated now, so I thought I will ask here before I delete it.

I managed to style the custom form 1 to reflect design of my website. Here is the code:

<div class="tnp tnp-subscription">
<form method="post" action="https://esstec.sk/?na=s">
<div class="tnpf">
<div><input type="hidden" name="nlang" value=""></div>
<div class="tnp-field tnp-field-email"><input class="tnp-email" type="email" name="ne" id="tnp-1" placeholder="Váš e-mail" value="" required></div>
<div class="tnp-field tnp-field-button"><input class="tnp-submit" type="submit" value="Potvrdiť" ></div>
</div>
</form>
</div>


Also the custom CSS from advanced settings page:

.tnpf {
display: flex;
flex-wrap: wrap;
justify-content: center;
}
.tnp-subscription input[type=email] {
background-color: #2b2b2b;
color: #eeeeee;
padding: 22px;
width: 350px;
font-family: inherit;
}
.tnp-subscription input[type=submit] {
border: 2px solid #08a29e;
padding: 20px;
background-color: transparent;
font-family: inherit;
font-weight: 600;
letter-spacing: .1em;
text-transform: uppercase;
}
input.tnp-email:focus {
outline: none;
color: #eeeeee;
}
input.tnp-submit:hover {
cursor: pointer;
border: 2px solid #4abdb4;
}


Then placed the form to my index page:

[newsletter_form form="1" confirmation_url="https://www.esstec.sk"]


This plugin also created page called Newsletter, where the form is inserted:

[nesletter_form]


Problems:
- after submitting email address, the user gets redirected to the page created by this plugin. No message for the user, only the same form is present.
- The user receives an email, but clicking the edit profile in order to unsubscribe loads again the newsletter page with subscription form, no messages, nothing, but I can see the url is something like: https://esstec.sk/newsletter/?nm=confirmed&nk=7-50dc7a8ca9

Can anyone help pointing me in the right direction? What am I missing?

Thanks guys.