if you have ssh access you can change the password by following MySQL query
UPDATE wp_users SET user_pass = MD5('your-new-password') WHERE ID = 'any-admin-ID'
Or if you don't know any administrator account you can create one By
INSERT INTO wp_users (ID, user_login, user_pass, user_nicename, user_email, user_url, user_registered, user_activation_key, user_status, display_name) VALUES ('4', 'new-username', MD5('your-new-password'), 'Your Name', 'test@yourdomain.com', 'http://www.test.com/', '2021-06-17 00:00:00', '', '0', 'Your Name');
and assign it as administrator by following queries
INSERT INTO wp_usermeta (umeta_id, user_id, meta_key, meta_value) VALUES (NULL, '4', 'wp_capabilities', 'a:1:{s:13:"administrator";s:1:"1";}');
INSERT INTO wp_usermeta (umeta_id, user_id, meta_key, meta_value) VALUES (NULL, '4', 'wp_user_level', '10');
*Replace wp_ with your DB prefix