Add this code to the Custom CSS field on the Appearance tab of your FAQ widget’s settings:
[class*="eapps-faq-search-bar-no-results"] {
font-size: 0 !important;
}
[class*="eapps-faq-search-bar-no-results"]:after {
content: "YOUR OWN TEXT/LANGUAGE"!important;
font-size: 1rem;
display: block;
text-align: center;
padding: 1rem;
}