Can't fill in the Hidden text area element

F1, need some help or hints with Hidden element using Robotframework.
The problem consist that to fill any text in the text area, I need to change the state of text area from display:none; to display:block;

Needed text area for input

Code that I see from WebDev Tool

The code itself:

<div class="col-md-12">
<div class="cazary" style="width: 664px;">
    <div class="cazary-commands-wrapper">
        <ul class="cazary-commands-list">
            <li unselectable="on" title="Size" class="cazary-command-fontsize">Size</li>
        </ul>
        <ul class="cazary-commands-list">
            <li unselectable="on" title="Foreground Color" class="cazary-command-forecolor">Foreground Color</li>
        </ul>
        <ul class="cazary-commands-list">
            <li unselectable="on" title="Background Color" class="cazary-command-backcolor">Background Color</li>
        </ul>
        <ul class="cazary-commands-list">
            <li unselectable="on" title="Remove Format" class="cazary-command-removeformat">Remove Format</li>
        </ul>
    </div>
    <iframe class="cazary-edit" src="javascript:" style="height: 39px;"></iframe>
    <textarea id="summernote" class="required-preview field cazary-source" placeholder="Tell us all about your Advertisement. This description will be prominently displayed in your Advertisement notice. Feel free to adjust the fonts and background colour too." name="observations" cols="50" rows="10" style="display: none;"></textarea>
</div>

My Robotframework code tries:

Select Frame      //iframe[@class="cazary-edit"]
# First try
Input text      //textarea[@id="summernote"]    ${UniversalVariableforName}
# Second try
Input text      //iframe[@class="cazary-edit"]    ${UniversalVariableforName}
# Third try
Input text      //div[@class="cazary"]//iframe[@class="cazary-edit"]    ${UniversalVariableforName}
# Fourth try
Input text      //body[@class="empty"]    ${UniversalVariableforName}
# Fifth try
Input text      //iframe[@class="cazary-edit"]//body[@class="empty"]    ${UniversalVariableforName}

Errors that were returned: image

May be there is a solution with Execute Javascript keyword?

The concerned <textarea> is outside of the <iframe class="cazary-edit">. Hence we don't need to switch to the <iframe>

To send the text to the Input field you can try to :

Use xpath as :

"//textarea[@class='required-preview field cazary-source' and @id='summernote']"

Click the Input field first.
Next Clear the Input field.
Finally try to send the text.

Update :

As the concerned textarea have the style attribute set as "display: none;", we have to change to "display: block;" through JavascriptExecutor then send the text.

Python Sample Code :

driver.execute_script("document.getElementById('ID').style.display='block';")