Allow all IP phpmyadmin centos

 Within this file, find the block below:

<Directory "/xampp/phpMyAdmin">
  AllowOverride AuthConfig
  Require local
  ...

Update this block and replace Require local with Require all granted, so that it looks like this:

<Directory "/xampp/phpMyAdmin">
  AllowOverride AuthConfig
  Require all granted
  ...

or centos   7

<Directory /usr/share/phpMyAdmin/>
   AddDefaultCharset UTF-8

   <IfModule mod_authz_core.c>
     # Apache 2.4
     <RequireAny>
      # Require ip 127.0.0.1
      # Require ip ::1
   Require all granted

</RequireAny>
   </IfModule>