How to send a char array in a custom characteristic?

Question

Hi, I've been trying to build a custom characteristic and so far I can display a single digit number on my BLE app. My update value function looks like this: uint32_t ble_cus_custom_value_update(ble_cus_t * p_cus, uint8_t custom_value)
{
 NRF_LOG_INFO("In ble_cus_custom_value_update. 
"); 

 if (p_cus == NULL)
 {
 return NRF_ERROR_NULL;
 }
 uint32_t err_code = NRF_SUCCESS;

 ble_gatts_value_t gatts_value;

 if (p_cus->conn_handle != BLE_CONN_HANDLE_INVALID)
 {
 // Initialize value struct.
 memset(&gatts_value, 0, sizeof(gatts_value));

 gatts_value.len = sizeof(uint8_t);
 gatts_value.offset = 0;
 gatts_value.p_value = &custom_value;

 // Update database.
 err_code = sd_ble_gatts_value_set(p_cus->conn_handle,
 p_cus->custom_value_handles.value_handle,
 &gatts_value);
 APP_ERROR_CHECK(err_code);

 if (notifications_enabled)
 {
 NRF_LOG_INFO("Sending notification for whatever");
 uint16_t len = sizeof (uint8_t);
 ble_gatts_hvx_params_t hvx_params;
 memset(&hvx_params, 0, sizeof(hvx_params));

 hvx_params.handle = p_cus->custom_value_handles.value_handle;

 hvx_params.type = BLE_GATT_HVX_NOTIFICATION;
 hvx_params.offset = 0;
 hvx_params.p_len = &len;
 hvx_params.p_data = custom_value;

 err_code = sd_ble_gatts_hvx(p_cus->conn_handle, &hvx_params);
 APP_ERROR_CHECK(err_code);
 }
 }
} 
 
 And my add function looks like this : 
 static uint32_t custom_value_char_add(ble_cus_t * p_cus)
{
 uint32_t err_code;
 ble_gatts_char_md_t char_md;
 ble_gatts_attr_md_t cccd_md;
 ble_gatts_attr_t attr_char_value;
 ble_uuid_t ble_uuid;
 ble_gatts_attr_md_t attr_md;
 uint8_t init_value = 0;

 // Add Custom Value characteristic
 memset(&char_md, 0, sizeof(char_md));
 memset(&cccd_md, 0, sizeof(cccd_md));
 memset(&attr_md, 0, sizeof(attr_md));
 memset(&attr_char_value, 0, sizeof(attr_char_value));

 // Set permissions on the CCCD and Characteristic value
 BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
 BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
 BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);
 BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);

 // CCCD settings (needed for notifications and/or indications)
 cccd_md.vloc = BLE_GATTS_VLOC_STACK;

 // Characteristic Metadata
 char_md.char_props.read = 1;
 char_md.char_props.notify = 1;
 char_md.p_char_user_desc = CustomCharName;
 char_md.char_user_desc_size = sizeof(CustomCharName);
 char_md.char_user_desc_max_size = sizeof(CustomCharName);
 char_md.p_char_pf = NULL;
 char_md.p_user_desc_md = NULL;
 char_md.p_cccd_md = &cccd_md;
 char_md.p_sccd_md = NULL;

 // Define the Button ON press Characteristic UUID
 ble_uuid.type = p_cus->uuid_type;
 ble_uuid.uuid = CUSTOM_VALUE_CHAR_UUID;

 // Attribute Metadata settings
 attr_md.vloc = BLE_GATTS_VLOC_STACK;
 attr_md.rd_auth = 0;
 attr_md.wr_auth = 0;
 attr_md.vlen = 0;

 // Attribute Value settings
 attr_char_value.p_uuid = &ble_uuid;
 attr_char_value.p_attr_md = &attr_md;
 attr_char_value.init_len = sizeof(uint8_t);
 attr_char_value.init_offs = 0;
 attr_char_value.max_len = sizeof(uint8_t);
 attr_char_value.p_value = &init_value;

 return sd_ble_gatts_characteristic_add(p_cus->service_handle, &char_md,
 &attr_char_value,
 &p_cus->custom_value_handles);
} 
 
 Now, how do I send a character say : char test[20] = "Hello, World!" via this instead of a number? Any leads?