unable to enter href with target='_blank' in the field

I have a table with the field - longtext
On the Add page I try to enter the href link as -
href link
and it is working. Again I try to enter the text as -
href link
then the target=“_blank” has remove automatically and when I check the database only the target=“_blank” is not enter.

I try removing the “Use HTML Editor”
and also by using it.
Both the option remove the target=“_blank” and I am unable to use this option.
This is new added table and I have not write any Server Client Script.

That may be due to http://htmlpurifier.org/live/configdoc/plain.html#Attr.AllowedFrameTargets. To create your own HTML Purifier setting, you may try to use the server side global code, e.g.

$PurifierConfig = \HTMLPurifier_Config::createDefault();
$PurifierConfig->set(‘Attr’, ‘Attr.AllowedFrameTargets’, [‘_blank’]);