diff --git a/src/app/api/aos/instances/[id]/custom-domain/route.ts b/src/app/api/aos/instances/[id]/custom-domain/route.ts
index c456d2f..2f59ee2 100644
--- a/src/app/api/aos/instances/[id]/custom-domain/route.ts
+++ b/src/app/api/aos/instances/[id]/custom-domain/route.ts
@@ -183,9 +183,10 @@ export async function PATCH(req: Request, { params }: { params: Promise<{ id: st
       try {
         await dokploy.createDomain({
           applicationId: instance.dokployAppId,
-          hostName: instance.customDomain,
+          host: instance.customDomain,
           port: 3000,
           https: true,
+          certificateType: 'letsencrypt',
         })
       } catch (e) {
         // Non-fatal — domain verification still succeeded, Dokploy attach can retry
diff --git a/src/lib/dokploy.ts b/src/lib/dokploy.ts
index 8b99b93..0bc295e 100644
--- a/src/lib/dokploy.ts
+++ b/src/lib/dokploy.ts
@@ -259,17 +259,19 @@ export function createDokployClient(config: DokployConfig) {
 
   async function createDomain(input: {
     applicationId: string
-    hostName: string
+    host: string
     path?: string
     port?: number
     https?: boolean
+    certificateType?: string
   }): Promise<DokployDomain> {
     const res = await call<{ domainId?: string; id?: string }>('/domain.create', {
       applicationId: input.applicationId,
-      hostName: input.hostName,
+      host: input.host,
       path: input.path ?? '/',
       port: input.port ?? 3000,
       https: input.https ?? true,
+      certificateType: input.certificateType ?? 'letsencrypt',
     })
     const domainId = res.domainId ?? res.id
     if (!domainId) {
@@ -277,7 +279,7 @@ export function createDokployClient(config: DokployConfig) {
     }
     return {
       domainId,
-      hostName: input.hostName,
+      hostName: input.host,
       applicationId: input.applicationId,
       https: input.https ?? true,
     }
@@ -349,9 +351,10 @@ export function createDokployClient(config: DokployConfig) {
     try {
       domain = await createDomain({
         applicationId: app.applicationId,
-        hostName: input.subdomain,
+        host: input.subdomain,
         port: 3000,
         https: true,
+        certificateType: 'letsencrypt',
       })
     } catch (e) {
       // Domain creation is non-fatal — app is already deployed