diff --git a/dnsapi/dns_lexicon.sh b/dnsapi/dns_lexicon.sh
index c09f16f..ab180fb 100755
--- a/dnsapi/dns_lexicon.sh
+++ b/dnsapi/dns_lexicon.sh
@@ -7,20 +7,13 @@ lexicon_cmd="lexicon"
 
 wiki="https://github.com/Neilpang/acme.sh/wiki/How-to-use-lexicon-dns-api"
 
-########  Public functions #####################
-
-#Usage: add   _acme-challenge.www.domain.com   "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
-dns_lexicon_add() {
-  fulldomain=$1
-  txtvalue=$2
-
-  domain=$(printf "%s" "$fulldomain" | cut -d . -f 2-999)
-
+_lexicon_init() {
   if ! _exists "$lexicon_cmd"; then
     _err "Please install $lexicon_cmd first: $wiki"
     return 1
   fi
 
+  PROVIDER="${PROVIDER:-$(_readdomainconf PROVIDER)}"
   if [ -z "$PROVIDER" ]; then
     PROVIDER=""
     _err "Please define env PROVIDER first: $wiki"
@@ -33,46 +26,73 @@ dns_lexicon_add() {
   # e.g. busybox-ash does not know [:upper:]
   # shellcheck disable=SC2018,SC2019
   Lx_name=$(echo LEXICON_"${PROVIDER}"_USERNAME | tr 'a-z' 'A-Z')
+  eval "$Lx_name=\${$Lx_name:-$(_readaccountconf_mutable "$Lx_name")}"
   Lx_name_v=$(eval echo \$"$Lx_name")
   _secure_debug "$Lx_name" "$Lx_name_v"
   if [ "$Lx_name_v" ]; then
-    _saveaccountconf "$Lx_name" "$Lx_name_v"
+    _saveaccountconf_mutable "$Lx_name" "$Lx_name_v"
     eval export "$Lx_name"
   fi
 
   # shellcheck disable=SC2018,SC2019
   Lx_token=$(echo LEXICON_"${PROVIDER}"_TOKEN | tr 'a-z' 'A-Z')
+  eval "$Lx_token=\${$Lx_token:-$(_readaccountconf_mutable "$Lx_token")}"
   Lx_token_v=$(eval echo \$"$Lx_token")
   _secure_debug "$Lx_token" "$Lx_token_v"
   if [ "$Lx_token_v" ]; then
-    _saveaccountconf "$Lx_token" "$Lx_token_v"
+    _saveaccountconf_mutable "$Lx_token" "$Lx_token_v"
     eval export "$Lx_token"
   fi
 
   # shellcheck disable=SC2018,SC2019
   Lx_password=$(echo LEXICON_"${PROVIDER}"_PASSWORD | tr 'a-z' 'A-Z')
+  eval "$Lx_password=\${$Lx_password:-$(_readaccountconf_mutable "$Lx_password")}"
   Lx_password_v=$(eval echo \$"$Lx_password")
   _secure_debug "$Lx_password" "$Lx_password_v"
   if [ "$Lx_password_v" ]; then
-    _saveaccountconf "$Lx_password" "$Lx_password_v"
+    _saveaccountconf_mutable "$Lx_password" "$Lx_password_v"
     eval export "$Lx_password"
   fi
 
   # shellcheck disable=SC2018,SC2019
   Lx_domaintoken=$(echo LEXICON_"${PROVIDER}"_DOMAINTOKEN | tr 'a-z' 'A-Z')
+  eval "$Lx_domaintoken=\${$Lx_domaintoken:-$(_readaccountconf_mutable "$Lx_domaintoken")}"
   Lx_domaintoken_v=$(eval echo \$"$Lx_domaintoken")
   _secure_debug "$Lx_domaintoken" "$Lx_domaintoken_v"
   if [ "$Lx_domaintoken_v" ]; then
+    _saveaccountconf_mutable "$Lx_domaintoken" "$Lx_domaintoken_v"
     eval export "$Lx_domaintoken"
-    _saveaccountconf "$Lx_domaintoken" "$Lx_domaintoken_v"
   fi
+}
+
+########  Public functions #####################
+
+#Usage: dns_lexicon_add   _acme-challenge.www.domain.com   "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
+dns_lexicon_add() {
+  fulldomain=$1
+  txtvalue=$2
+
+  if ! _lexicon_init; then
+    return 1
+  fi
+
+  domain=$(printf "%s" "$fulldomain" | cut -d . -f 2-999)
 
   $lexicon_cmd "$PROVIDER" create "${domain}" TXT --name="_acme-challenge.${domain}." --content="${txtvalue}"
 
 }
 
-#fulldomain
+#Usage: dns_lexicon_rm   _acme-challenge.www.domain.com   "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
 dns_lexicon_rm() {
   fulldomain=$1
+  txtvalue=$2
+
+  if ! _lexicon_init; then
+    return 1
+  fi
+
+  domain=$(printf "%s" "$fulldomain" | cut -d . -f 2-999)
+
+  $lexicon_cmd "$PROVIDER" delete "${domain}" TXT --name="_acme-challenge.${domain}." --content="${txtvalue}"
 
 }